Chapter 2: Why We’re Fat Part 2

Chapter 2.

Why We’re Fat, Part 2—The Science of Size


You must unlearn what you have learned.

—Yoda, The Empire Strikes Back


As we learned in chapter 1, obesity is a multi-factorial condition. That means it has more causes than Cosmo has freaky sex tips.

In the simplest sense, however, obesity has just one cause: consistent positive energy balance. In English, this means taking in more calories than you burn. But before we get into that, I have to explain why calories matter.


Weight Loss Math

It’s really simple. If you have a caloric deficit, you lose weight. If calories are positive, you gain weight (we’ll get into making weight loss about fat loss later). Energy balance is a direct representation of the first law of thermodynamics, the one that says energy can neither be created nor destroyed. We’re not talking about a hypothesis here, or even a theory, but a physical LAW OF THE UNIVERSE. Ever hear of the law of gravity? A law is something scientists are so damn sure of that there’s no disputing it. You can’t deny the first law of thermodynamics any more than you can deny the fact that if you jump out of a high-flying airplane without a parachute, gravity will not be your friend. (Note to fans of The Secret: the “Law of Attraction” is not a real scientific law.)

And yes, I do know there are best-selling authors who question this law. They present themselves as “controversial.” They assert that years of accepted science are wrong. Let me ask you a question: the next time you get into an airplane, would you rather it was designed, built and tested in a scientifically proven manner, or in a controversial one?

I thought so.

Excess fat can’t be blamed on insulin, carbohydrates or the Loch Ness Monster. Gaining body fat comes from taking in more calories than you burn. Anyone who can prove otherwise will surely win a Nobel Prize in physics for disproving the first law of thermodynamics. I am unaware of that particular Nobel having been awarded.

Back on planet Earth, the link between weight loss and calories has been proven myriad times.

Rudolph Leibel et al. conducted a carefully controlled study in 1992, which was published in the American Journal of Clinical Nutrition and asserted that “variations in fat intake from 0% to 70% of total energy under conditions of equal energy intake produced no significant changes in body weight over periods of observation averaging 33 d [days].” In language that we can all understand: Leibel’s study put participants on balanced energy diets: they controlled to ensure that the participants took in the same number of calories that they burned over a 33-day period. The participants got a varied range of overall fat content, from 0 percent to 70 percent, but everyone’s weight stayed the same, once again proving the first law of thermodynamics.1

Why did the participants’ weight stay the same? Because they were on maintenance-level calories. It does not matter what percentage of protein, carbohydrates or fat you consume in the grander scheme of weight loss and gain. It’s all the simple formula of calories in minus calories out. Obesity researchers Alain Golay and Elisabetta Bobbioni, in their 1997 article “The Role of Dietary Fat in Obesity,” agree: “fat is almost exclusively used or stored in response to day-to-day fluctuations in energy balance.”2

In 2004 nutrition professors Andrea Buchholz and Dale Schoeller looked at the published data to answer the question, is a calorie a calorie? The results were published in the American Journal of Clinical Nutrition. The authors conducted a thorough metabolic analysis of the effects of diets that varied in fat, protein and carbohydrates and made this assertion: “We conclude that a calorie is a calorie. From a purely thermodynamic point of view, this is clear because the human body or, indeed, any living organism cannot create or destroy energy but can only convert energy from one form to another.”3

Beyond this, there is so much research that proves the whole calories-in vs. calories-out rule4 that any arguments claiming that weight loss is something other than an energy balance issue are as real as professional wrestling. What’s more, I’ve interviewed a number of the world’s top obesity researchers, and for every one it’s a “well, duh!” that weight loss is calories in versus calories out, regardless of the type of calories.

If you eat 2,000 calories of chicken wings and butter-fried pork rinds a day, yet burn 2,500 calories a day, you will lose weight. You will also be one unhealthy bugger.

If you eat 3,000 calories of spinach, carrots and egg whites a day, yet burn 2,500 calories a day, you will gain weight. Harsh, but true.


The Twinkie Diet

Is this sinking in? Although it didn’t qualify as an official study, Mark Haub’s experiment bears consideration. Haub is a nutrition professor at Kansas State University, although you may know him better as “Twinkie Guy.” In 2010, Twinkie Guy proved he could lose weight living mostly on Twinkies, Doritos, Oreos and other treats just by consuming fewer calories than he burned. He lost 27 pounds in two months, though I imagine that due to the low satiety factor and high reward value of the food, he must have felt he was starving the entire time. He didn’t do the experiment to endorse a junk food weight loss program but to prove a point: calories are all that matter to weight loss.

As we’ll show, it’s far easier to sustain a lower caloric intake when food is healthy than when it’s sugary-fatty-salty crap. Remember that sustainable weight loss is about finding a healthy way to have a reasonable caloric deficit while losing weight and then finding a healthy way to sustain caloric balance when you achieve your target weight.


Beyond the Numbers

In chapter 1, and at the beginning of this chapter, I mentioned that a positive energy balance (taking in more calories than you need) has multiple causes. Let’s get graphic and check out some of them.

Mediators of Energy Balance and Body Weight. (Used with permission.)


This figure is taken from a 2012 article by University of Cambridge researchers published in Nature Reviews.5 It lists the wide variety of factors that contribute to overweight and obesity. Yup, there are a lot of them. For now let’s look at one you can’t change.


Genetics and the Art of Sucking It Up

Heredity is not destiny.

If you saw my parents in their swimsuits you’d understand that I’m not genetically programmed for leanness. (And now I’m out of their wills.)

That being said, some of us are naturally inclined to be heavier than others. However, recall the stat that we threw out at the beginning of the previous chapter, the one about the doubling of obesity rates in the United States in only 24 years. The genetics of humanity do not change so quickly; the rapid rise must be coming from those environmental causes we discussed. However, the way in which individuals react to this new environment can be genetic. It can also be epigenetic: the environment modifies the way your genes are expressed. Creepy.

Here’s the thing. Your genes are what they are. You can’t change them. There’s far more that we don’t know about the genetic causes of obesity than we do, so it doesn’t make sense to do a massive deconstruction of the various genes that may or may not make you more susceptible to weight gain. This is one of those things that fall under the heading “Suck It Up.”

Some people have to work harder than others to be fit and healthy, but it’s important to know that even for those of us genetically programmed to be overweight, hard work can get ’er done. Need proof? Let’s look at the Pima Indians. Several studies have compared a group of Pima in Arizona with Pima in a remote area of Mexico. The two groups have a shared genetic background programmed by their specific evolutionary circumstances to gain weight easily so they could live through frequent famines, but their circumstances are not at all alike. The Arizona Pima have a lifestyle that requires far less manual labor and provides access to ample high-calorie foods. As a result, the Arizona tribe has one of the highest rates of obesity and type 2 diabetes in the world. By contrast, women in the Mexican Pima tribe are just barely overweight on average, and most men are in the normal weight range.6

Unlike in Arizona, Mexican Pima live a Spartan existence with much physical activity and moderate caloric intake. Even though they are genetically programmed to be overweight, their lifestyle has created a different outcome. Granted, that lifestyle is one of poverty, but from a genetic perspective it provides proof that no one is destined to be fat. Some people just have to work harder at controlling their weight. The unlucky ones have to work exceptionally hard.

You may have been screwed in the genetic lottery, but I’m about to go all tough love on you. You’ve got to play the hand you’re dealt. There is not one damn thing you can do about your DNA, so it, more than anything else, is something you’re just going to have to live with. You may not be destined to look like a fitness model—few of us are—but you can improve. You can work with what you’ve got.

As the old US Army slogan said, Be all you can be.


Your Brain on Food

Still friends after that tough love bit? Great. Let’s move on to learning about how your brain reacts to the food you eat and how that affects your weight and your health.


Reward Systems Run Amok

Have you seen Trainspotting, that movie about heroin addiction? It’s a serious bummer and I don’t recommend it.

There’s a scene in which a woman injects the drug for the first time and she says … well, I can’t write what she says because I’m trying to keep things PG. Anyway, she suggests that heroin is way better than sex. I’d never touch heroin, so I can’t weigh in on the debate, but it does make me wonder what kind of lame lovers she’s had.

Why all this talk of heroin? Because although the degree is far less, highly palatable food hijacks your brain’s reward system in the same manner.7


Why We Like What We Like

Think of an apple. Imagine taking a big bite. Even if you love apples, you can’t imagine eating six of them at once, right? Because no matter how good they are, it’s not as though your mouth just had an orgasm, is it?

Crème brûlée, though? Or cookie dough ice cream? Or “Mmmm … I love Turtles”? Total mouthgasm.

Unlike a real orgasm, however, junk food doesn’t offer much of an afterglow. Plowing through half a pizza or a box of chocolates may make you feel good for a few minutes, but that feeling doesn’t stick around for the rest of the day. A sexual romp can keep you sated for a long time, but junk food begets more junk food: you keep eating well beyond the point of bodily energy requirements, losing track of how much you ate and being unable to tell whether you’re still hungry. Why do you do this? Because the reward is outstanding. Before you know it, the compulsion grows, and you need ever more sugar, salt and fat to quench the desire for the next mouthgasm.

I’m going to stop writing that word now, okay?

Here’s the thing: evolution programmed us to like certain flavors. One of the reasons we like sweetness is that it represents nutrition. A piece of fruit is at its nutritional peak when it’s at its sweetest. For the millennia of human evolution, seeking out sweetness was good—until technology started messing with things and making nutritionally vacant yet calorically dense hyper-flavored sugar-fat combination treats like hot fudge sundaes. What’s more, such foods are soft rather than crunchy, allowing for a fast ingestion that generates an immediate sense of pleasure. It seems similar to the difference between smoking heroin and injecting it.

Have you ever had a perfectly ripe mango? It’s one of the most amazing-tasting natural foods on the planet. One mango has about 130 calories. How many can you eat? I’ve tried to eat more than one in a sitting, but halfway through the second I didn’t want any more. Something in my brain shuts down so a second one doesn’t seem that appealing, no matter how good the first one tasted.

Compare that with a high-sugar/high-fat restaurant dessert such as the Keg’s carrot cake à la mode. It has 2,344 calories. That’s 18 times as many calories as a mango. I know I would eat the whole thing and then lick the plate clean; the flavor is so overwhelming that all appetite control is lost. (Then I’d have to do a full marathon worth of running to burn it off. Think on that math.)

So what the hell is going on here? It’s neuro-chemistry. Sugar, fat and salt all create a chemical cascade in your brain, an intricate interaction of hormones, neurotransmitters, endorphins, satiety signals and reward sensations. Mangos are a simple taste of natural sweetness—delicious, yes, but we get bored with it quickly. Processed treats, on the other hand, amplify and combine flavors to create an overwhelming taste sensation that’s hard to get tired of. And some people have it worse than others. These poor folk are more “reward sensitive” than the average Joe, and they crave the fix that drugs, alcohol or highly palatable (extra-yummy) food gives them more intensely. Others are what we call “super tasters,” experiencing greater taste intensities, both positive and negative. They’re more likely to love sweet foods, for example, and hate the bitterness of vegetables.

To get all science-y on you for a minute, what we’re talking about here is basic operant conditioning psychology related to the stimulus-response model of behavior change. If a stimulus (such as putting a chocolate bar into your mouth) elicits a positive response (such as thinking, Whoa, Mama, that tastes good), the stimulus behavior is reinforced and you seek out that rewarding feeling again and again. It works the other way as well, where a bad taste is seen as punishment, causing you to avoid foods you don’t like.


Trying to Love the Green Stuff

Broccoli is so good for you. I wish I liked it.

Blarf. Hate the stuff. I’ve tried. Can’t do it.

There are, however, other green vegetables I have managed to develop a taste for, but it took effort. You know what doesn’t take effort? Liking cherry pie with vanilla ice cream.8 And that type of “like” goes way beyond “developing a taste.” It’s not the same with vegetables, where I can say, “Yeah, this tastes okay. I’ll eat it because I know it promotes satiety and is good for me.” With a yummy dessert, or cheeseburgers, chicken wings, pizza, chocolate, potato chips, etcetera, it’s, OMG, so good that I can’t restrain myself—must have more!

When I’m faced with such a dessert it takes an effort of will to not eat it in the first place,9 because my brain has been conditioned to know it’s an instantaneous source of massive pleasure.10 And if I start eating it, it’s hard to stop.11

With the veggies, however, it’s as if I have to force myself to finish them.

Right now, you’re all like, “Well, duh. One tastes so-so and the other tastes amazing.” Yes, that is correct. And how these differing tastes affect your brain and cause weight gain is what we’re about to get into. It’s more complex than yummy versus bitter.

What you eat isn’t just about how it tastes. Yes, we’ve just learned that there is a psychological aspect of “positive reinforcement,”12 and that this works in reverse as well, where bad-tasting foods are avoided. Beyond this, however, there are also metabolic, endocrine and genetic factors at play.13 Interestingly, though, it still boils down to the way highly palatable food makes you feel.


What’s Going on in There?

It’s all about the hippopotamus.

Wait, what? Oh, sorry. Hypothalamus. My co-author Margaret insists it’s the hypothalamus, and she would know, because of the PhD in neuroscience psychology something something. This is where it is in your brain:

Credit: David Lewis

What my co-author looks like without all that hair, skin and skull getting in the way.


There is much recent research about the metabolic and neural feedback signals that are responsible for our desire to eat.14 Many of these are generated in the hypothalamus, which is like a thermostat for your body. It regulates internal temperature, hunger, thirst and sleep cycles.

            So far, so good. If hunger were just a matter of hypothalamic inputs, the brain could hypothetically adjust our appetites to keep our bodies in a healthy weight range; it could stop us from eating when we’d had enough to meet our daily energy requirements.

But that ain’t happening.

Our ability to regulate food intake “cannot withstand the strong environmental pressures in most individuals,” said Hans-Rudolph Berthoud, neurobiology of nutrition professor at the Pennington Biomedical Research Center in Louisiana. “Our brain is designed to strike a balance,” Nicole Avena told me. “But our brain can sense if we’re deficient in nutrients. It’s possible to be overfed but undernourished.” At least, it’s been possible in the past century. Junk food provides a lot of calories but little nourishment. For most of human history we didn’t have this problem; things are now out of balance. “And the brain is still seeking out those essential nutrients, so it sends out more hunger signals to get them. There is a cognitive element to getting the vitamins and nutrients we need.”

Runaway food consumption is a breakdown between two systems that drive eating. One is physiological, called homeostatic hunger.15 It regulates your body’s need for sufficient calories to maintain homeostasis.16 In less scientific terms, it’s about fueling your daily energy requirements, and not much else.

The other system is psychological, called hedonic hunger. Think of the word hedonism. It’s all about the pleasure, baby.

Physiological hunger—the kind that keeps weight “normal”—is guided by signals sent from the gut, blood and hypothalamus sensing levels of glucose and amino and fatty acids.17 If you are experiencing this type of hunger because your body needs food, just about anything is going to taste good.

I remember being out for a run once and “bonking,” which is a runner’s term for, Oh God need food now feel wretched can’t run without food please feed me. I made it back to my car ready to eat the steering wheel and found a prehistoric granola bar that my wife had left in the glove box. I don’t dig granola bars, especially ones whose best-before date are from around the time a baby Justin Bieber burst out of an alien torso, but I wolfed that sucker down as if it was the antidote to fast-acting poison, and it was scrumptious. (Bonking, by the way, is not “working up an appetite.” It’s low blood sugar remedied with minimal calories.)

On the other side of the equation, psychological hunger—eating for pleasure—arises from a chain of events that start in the middle of the brain, and that bitchin’ vibe you get from eating something sweet and fatty hits those same reward paths as drugs, alcohol, gambling and even sex.18 This is about cravings. You don’t need to eat this tasty food, but you want it.

You want it bad. Even though you know it makes you gain weight. Even though you know it’s not good for you. The reason why you want it is because of …


Primary Rewards

A “reward” is a stimulus that alters and reinforces behavior.19 The reward system is nature’s way of making sure we don’t die.

Here are some examples of primary rewards:

Examples of rewarding behavior Reward generated
When this thing between my legs touches the thing between that other person’s legs it feels really good. Continuation of the species.
When my mouth feels as if it’s been sandpapered with the Gobi desert, a big glass of water feels really good. Not dying of thirst.
When I’ve been awake and working for days on end, falling asleep even on a pile of rocks feels really good. Prevention of sleep-deprivation psychosis and eventual death.


When I’ve eaten a lot of food and things work their way southward, going to the bathroom feels really good. Not exploding and blowing partially digested food all over creation like something out of aMonty Python movie.


Okay, sorry about that last image, but you get the idea. Eating is a rewarding behavior that nature programmed into us so we’ll be compelled to seek food and therefore not die. Not dying so you can live long enough to do that rewarding touching of things between the legs stuff is what evolution via natural selection is about.


The Prime Suspect

There really isn’t any suspicion about what causes overeating. This sucker is guilty.

It’s called the mesolimbic dopamine reward pathway. When we engage in behavior that enhances survival (fornicating, eating, sleeping, not exploding) this neural pathway is activated.20 Dopamine is fired from within the limbic system, which resides deep within the brain. Specifically, dopamine comes from the ventral tegmental area and into the nucleus accumbens.

I thought those were big words too. Let’s just refer to it as the “hedonic hot spot.”21

Unfortunately, not all rewarding behaviors have value in prolonging life. Some of them are downright counter to survival, like the unnaturally rewarding effects of drugs, alcohol and overeating highly palatable food.


The Survival Mechanism

Here’s the problem, which is also the explanation.

Even with an awful diet, you can live long enough to procreate. These days, vegetables are great for promoting a healthy body weight. They offer a large volume of food for a low number of calories, they contain fiber, which also makes them more satiating, and they take a lot of chewing, which slows the eating process. They’re also not the tastiest things around, which ensures that you tire of eating them before you overconsume. In the current food environment, vegetables are your friends when it comes to keeping weight down, not to mention all the nutritional and cancer-fighting benefits they have.

Cavemen and women didn’t care about any of that. Cancer? What the hell is that? These guys were lucky to live to 30, and they wanted as many calories as they could get, because starvation was Enemy Number One, even more so than the saber-toothed murder beast. Starvation is still an issue; it has killed more people throughout human history than anything else.

I shall repeat: Starvation has killed more people throughout human history than anything else. Gives you some perspective, doesn’t it?

Back to the point at hand. “The energy density in fat and sugar is really high,” Eric Stice, an eating specialist and senior scientist at the Oregon Research Institute, told me. “So if we find Brussels sprouts alongside sugar beets, we will choose the beets because our body wants more energy-dense foods. It was a survival mechanism.”

Something low calorie, like spinach, didn’t do nearly as much to enhance a troglodyte’s chances of survival as something sweet or fatty did, because of the energy difference. People living on the brink of starvation were programmed via natural selection to cram in as many calories as possible, which caused them to seek out sweet fruits and fatty meats. And if you mix sweet and fatty together, watch out. That’s why chocolate—which contains both sugar and fat—has such a high reinforcement value.22

This sense of pleasure is innate. We don’t need to learn to like it. It’s why I was able to watch my son plow through a big piece of chocolate cake on his first birthday with undisguised glee on his face. I mean, what I could see of his face through the layers of frosting.


Going against Gut Instinct

Time for a reality check: your body has no wisdom when it comes to food.

Some alternative practitioners speak of the “wisdom of the body,” and hold that humans have an inherent system designed to seek out only the nutrients we need.

Did anyone else just hear a flock of ducks go by? Quack, quack, quack …

If this was the case, we’d have a kale shortage and childhood obesity would not exist. The only things the body—and brain—respond to immediately are sugar, fat and salt. This is because each of these compounds produces an immediate signal to the brain, telling it that they hold value: energy to allow for movement (like hunting for more food and procreating) and to build up fat stores to survive the next famine.

Salt, of course, is an exception in that it doesn’t contain calories, but it is nevertheless critical to survival.23 It’s important for brain development, and the salt that’s sweated from our bodies also needs replacing. Food companies have used it liberally to make their products taste better and promote additional consumption.24

In short, the body wants what it wants, and it does not have a magical mechanism for obesity prevention. Neither do dogs, by the way, animals that are suffering their own obesity crisis and will eat chocolate with abandon even though it is toxic for them. Canine bodies have no more wisdom to prevent obesity than human bodies do. Obesity rates prove that our tastes are pretty basic, and in this land of constant plenty, most of us are going to gain weight.

There is no magic mechanism, but there is consciousness. Later in this chapter we will provide advice on how to think your way past your baser food desires.


The Highly Palatable Painkiller

To reinforce just how profound the effect of highly palatable food is on the pleasure centers of the brain, it’s worth pointing out that such foods can actually dull or at least distract us from painful experiences. Doctors use the tactic of placing a little sugar solution into a newborn baby’s mouth before taking blood to prevent or at least mollify the patient’s wails.25

The hormonal alchemy of sucrose placed on the baby’s tongue activates a dopamine and opiate rush that masks the sense of pain associated with the needle.

            Let’s drive home with some imagery that point about intuitive eating being a crock. We’re born to love sweetness and have to learn to appreciate bitterness (like what is found in vegetables).

To prove it’s innate, Margaret put her scientist cap on and she experimented on her friend’s baby (with parental permission, naturally) while I snapped photos.

“Sugar elicits a feeling of pleasure,” Margaret said. “We tell that by the baby’s smiling.”

This is the happy face of the five-month-old baby girl after having a sugar solution placed on her tongue:

It’s blurry because she’s vibrating with joy.


“Bitter tastes,” Margaret said, “unfortunately send a message to the brain that you’re eating something poisonous, so the reaction is crying and fussing. Historically, vegetables were not worth our time to eat because they lacked energy density, which is why the learning process to accept vegetables is difficult.”

And so, this is your kid on spinach:

Why are you doing this to me?


Mixing Uppers and Downers into Tasty Speedballs

In case we haven’t made it clear: obesity is caused to a significant degree by pleasure-focused eating. This is the “hedonically motivated” kind of consumption where we lose control because the food tastes so good, making those reward pathways in the brain commence firing away like a scatter gun at a hillbilly BBQ.

Pleasure is the result of a kind of chemical alchemy traced to two major hormones in the brain: dopamine and opioids.26 Dopamine and opioids are involved in the sensation and expectation of pleasure, and we experience a surge in both when we eat junk food.

A “speedball,” in drug vernacular, is a mixture of an “upper,” in the form of cocaine, and a “downer,” in the form of heroin or a like substance.


The Upper: Dopamine

It can be hard to unlearn what you have learned.

Last week, my wife went to Costco and bought a giant tin of Almond Roca for stocking stuffers.

Uh, hello? IT’S MONTHS UNTIL CHRISTMAS! This is like buying Halloween candy in August.

I know there is Almond Roca in my house. ALMOND ROCA IN THE HOUSE! I know where it is. I know it’s on a shelf down in the basement right next to the dryer. I know the container is pink and cylindrical and has a gold plastic lid. I can see the shape and size of the golden-foil-covered treats inside. I could draw one from memory. I know what it’s going to taste like. I know it’s there. I know it tastes good. I know I want it. The pleasure centers in my brain have burned all of this into memory.

Excuse me for a moment.

Oh, wow. That was good. And now, a message for my lovely wife: WHAT THE HELL WERE YOU THINKING? Do you believe there will be ANY of those left by the time Christmas arrives?

I do love her, so I won’t blame her. I’ll blame dopamine (and opioids) instead.

The role of dopamine has been the focus of scientific debate, and while it is still under investigation we know it plays a part in pleasure, learning and craving. When a survival-enhancing behavior is completed, dopamine is fired. Engaging in rewarding behavior increases the level of dopamine transmission in the brain and directs our attention in preferences to things that make us feel great.27

Dopamine also fosters a strong positive memory; it encourages our search for rewards that elicit the most pleasurable experiences.28 That’s why I know so much about Almond Roca, and why I can draw an accurate map from memory of every fast food restaurant within a five-mile radius of my house, and yet I can only guess at what vegetables are in my fridge right now.

Dopamine is what makes us crave highly palatable food. Its firing goes beyond the sensation of pleasure experienced when eating that food to include the encoding into memory of that experience so we will seek out such foods again in the future.

One of the reasons it’s difficult to control these cravings is the expectation of the reward we’ll receive once we satisfy them. We know food X, Y or Z is going to taste good, so we want it.


The Downer: Opioids

Opioids are another kind of neurotransmitter that helps determine food preference. The weight of scientific evidence on the subject supports opioids enhancing the pleasure factor of eating, making the experience more rewarding and causing people to seek out such effects again and again despite the known negative consequences associated with doing so (such as weight gain).29

Opioids are responsible for the hedonic impact of food.30 Just like the heroin (an opiate) in a speedball produces euphoria, so do things like chocolate. But as Prof. Leigh Gibson pointed out in chapter 1, the euphoric effects of junk food are short-lived.

And these buggering opioids are even more nefarious. They act within the brain’s reward pathways in ways that inhibit satiety.31 This means that foods high in hedonic value—the ones that taste best—trigger a response from opioids that not only say, “This is awesome,” but also insist, “No, we’re not even close to being full. Keep shoveling more in.”

It’s worth noting that the discovery of the opioid systems stems from the use of opium. Go figure. Morphine is the most active ingredient of opium and remains a popular painkiller despite an array of adverse side effects (drowsiness, tolerance, dependence). Heroin was synthesized from morphine and today is a main illicit drug of abuse.

Opiates stimulate the opioid system; highly palatable food stimulates the opioid system.32 Got it? Scary, right?



Chocolate: The Socially Acceptable Speedball

“I hate chocolate,” said no one, ever.

Chocolate is one of the most craved substances in the United States.33 The inclusion of caffeine in the mixture accounts for some of this, but the draw is mostly due to the mixture of sugar and fat. Each on its own is rewarding enough, but merge them into one treat and it’s a recipe for neurochemical reward pathways run amok.

Eating a sugar-fat combination, like chocolate, activates both dopamine and opioid circuits in concert. You have the upper and the downer effect at the same time. Although the effect is not to the same degree, chocolate is like a legal, socially acceptable speedball. Sugar is the cocaine giving you the “high,” and fat is the heroin giving you that relaxing, euphoric “mmmm.”

It’s a compelling sensation, and it makes you want more. The opioids say what you’re doing is pleasurable and therefore must enhance survival, and the dopamine says the body is getting what it needs—energy—so that must enhance survival too.34

“The most powerful foods are the ones that combine sweetness and fat,” Leigh Gibson told me. “We do find with stress eating that chocolate is the number-one preferred food.”

You probably knew that already.




ADHD and the Risk of Obesity

ADHD—attention deficit hyperactivity disorder—can make you fat. Look! A puppy!

“There are strong links between ADHD and obesity,” Prof. Carolyn Davis told me. “Those who are more inattentive are more impulsive.” And impulsivity translates to a higher ingestion of palatable food. “Another reason is the lack of planning associated with the disorder and the need for immediate gratification.”

Harvard neurologist Dr. Miguel Alonso-Alonso agrees. “We know that people with ADHD have higher rates of obesity than the rest of the population,” he said. “Impulsive people have more acute responses that are more driven by the environment.” And the environment is rich in highly palatable food.

Medication can help, but so can exercise as a tool to ameliorate impulsivity.



Hijacking the Reward System

So now you know that just because something feels good doesn’t mean it’s good for you. Scientists refer to behaviors or substances that elicit extreme reward—by releasing an unnatural amount of dopamine and opioids on ingestion—as being capable of hijacking the reward system.35

The natural foods consumed by our ancestors didn’t pose this problem. The opium poppy doesn’t mess with you the way its refined street version does. Even the marijuana of yesteryear pales in potency compared with modern-day ganja.

Humans messed with food and drugs and made them all way more powerful, and that added power is now screwing with our brains. Recall the question I posed earlier: how many calories of mangos can you eat in one sitting compared with how many calories of carrot cake à la mode?


The Dopamine Tsunami—Too Much of a Good Thing

Scientists believe that, just as happens with certain drugs, consuming too much highly palatable food will dim the dopamine receptors.36 The dimming or pruning of dopamine receptors leads to an enhanced tolerance for junk food, which leads to wanting more junk food. The end result? A situation in which you only feel like eating junk food and end up gaining weight as a consequence.

How does this happen? Imagine an ocean. Now imagine a forest right next to this ocean. When you ingest substances (such as foods high in sugar and fat) that release a massive “wave” of dopamine, this wave acts like a tsunami. It crashes into the forest (where the trees are your dopamine receptors) and wipes out a bunch of trees.

But we need those trees. They’re an integral part of the overall ecosystem known as your brain and body. If there are enough dopamine tsunamis, more and more of the trees/receptors get knocked down. They’re overwhelmed and destroyed, leaving behind a barren landscape.

And it gets worse. Now that your body and brain are used to these massive, havoc-wreaking surges of dopamine, it takes even more of the original substance to create the same-sized tsunami, and there are fewer and fewer trees left to absorb it. This is what you call a vicious circle.

Ever hear of drug abusers first taking the substance to feel good but then building up a tolerance to the point that they need more and more of the drug to achieve the same effect? After a while, the poor souls are taking the drug just to stop feeling bad. The same thing can happen with food.

Here is what the vicious circle of food compulsion looks like:


“The more you overeat energy-dense foods,” Eric Stice says, “the less reward you get and the more you need to eat to get that reward. You need a larger and larger dose.”

This phenomenon is called raising the reward threshold. Cocaine does it. Heroin does it. And building research suggests that too much highly palatable food does it as well.37

A 2001 study published in The Lancet showed brain scans of 10 obese men and women and 10 controls. It found that dopamine receptors were decreased in obese individuals in direct relation to body mass index. The authors compared frequent consumption of highly palatable food to alcohol, cocaine and opiate abuse and found the effect on dopamine receptors to be similar.38

And a 2012 study of 151 healthy-weight adolescents published in the American Journal of Clinical Nutrition found that frequent consumption of ice cream, independent of body-fat levels, resulted in a reduction in “reward-region responsivity in humans, paralleling the tolerance observed in drug addiction.”39

In other words, you don’t need to be overweight before the dopamine receptor pruning begins.

 “The system that suppresses impulses to overeat is a limited resource,” Dr. Alonso-Alonso told me. “These areas of the brain can be exhausted quickly. We are overusing the control systems because of the current environment.”

Dr. David Katz, founding director of the Yale University Prevention Research Center and an authority on nutrition and weight management, sums it up nicely: “The food industry, when they said, ‘Bet you can’t eat just one,’ weren’t kidding around.”

Do you now see why you need every tool you can muster, such as integrating exercise into the equation to help you control food cravings? (We’ll cover how exercise affects appetite in chapter 4.) I’m good at managing food intake, as is evidenced by my four-pack abs (hey, if I was great at it I’d have a six-pack), and yet I have a hard time resisting that Almond Roca stash because I know I have 24/7 access to it. If it weren’t in the house, the desire to go get some would be manageable. Successful resistance involves removing temptation. In a 2013 study published in Neuron, Molly Crocket, a neuroscientist at University College London, and her colleagues describe this as “precommitment,” which is a “voluntary restriction of access to temptations.” The research team found that such precommitment is a far superior dietary strategy than willpower in the face of temptation.40     

When someone is kicking the heroin habit, you don’t put her or him in a house full of heroin. This is why a key component of getting off junk food is to avoid it as much as possible. When you mix the effects of opiates and dopamine and consider how they react to the ingestion of junk food, we’ve got to do better than just out of sight; the junk’s got to be so far out of reach that seeking it out represents enough of a pain in the butt to cause you to rethink your desire.


Why There’s Always Room for Dessert

One of the best meals I ever had was on a cruise ship. It was all just so good and I stuffed myself to the gills. I couldn’t eat another bite.

And then the crème brûlée showed up.

I ate it.

This is sensory-specific satiety in action. It refers, in scientific terms, to the declining satisfaction generated by a specific type of food the more you eat of it, and the consequent appeal of a new food that allows you to keep eating once full of something else.41

In a 1986 article in Nutrition Review on the subject of sensory-specific satiety, Prof. Barbara Rolls reports that “the pleasantness of the sensory properties of the eaten food decreases significantly more than the pleasantness of uneaten foods.” Rolls explains that this effect is greatest when the uneaten food is different in taste type to the eaten kind. In other words, a sweet dessert is always an option—even after a big steak.

This biological process is also advantageous from an evolutionary standpoint. “Sensory-specific satiety helps to ensure the consumption of a varied, and therefore balanced, diet. Thus, when a variety of foods are available, there will be a tendency to switch from one food to another because of the decrease in palatability in any one food after consumption,” reports Rolls.42

A number of other studies show that the more variety you have in your food, the more your satiety signals will get overridden and allow you to keep consuming past fullness.43

In a land of overwhelming choice and abundance, it’s all those options that encourage you to overeat. The stereotypical buffet feeding frenzy is just one example of the ways in which we override the system and consume far more calories than are needed to maintain body weight.44 Limiting your access to this endless variety is one strategy for controlling consumption. Another is to retrain your brain, on several levels.


Doing It Doggie-Style

Sorry, bad analogy. When I was a kid I saw my standard poodle eat until he puked, then eat the puke.

Pavlov’s dog: ring a bell and he salivates. Why? Because Fido had been conditioned to associate the bell with food.

Weaning yourself off junk food is all about retraining your brain, and that requires breaking with your past conditioning. We learn to like certain foods through this conditioning: we taste something, it’s rewarding (yummy!), and we remember it.45 Jersey Shore notwithstanding, we are the most advanced species on the planet thanks to the complex nature of our brains. We have an immense capability to remember associations between a certain food and the time, place and conditions under which it was consumed.46

When I smell candles being blown out, I think birthday cake. Hell, when I use the big Black & Decker massager on my neck and, after a while, it makes the same ozone smell as the mixer in my kitchen, I think birthday cake.

The principle of food reward gets exploited by pervasive advertising: grocery stores, TV, radio, online, magazines, newspapers … it’s everywhere. Images and advertisements about food send a powerful message to the most primitive parts of the brain, the same parts that are geared toward survival and don’t, therefore, take into account whether we need to eat.47 For most of human history we gorged when we could to put on lifesaving fat stores for a future famine. It didn’t matter if we weren’t hungry. The people who were best at this survived. And we descended from those survivors. Unfortunately, food advertisers take advantage of this survival mechanism.


Dairy Queen, Alice Cooper and the Fire Woman

My wife was out with the kids one day and I was watching TV; a Dairy Queen commercial for the Blizzard came on. I’m not much for Blizzards, but an image of the Peanut Buster Parfait entered my brain (that recall, by the way, was dopamine in action).

My kids are allergic to peanuts. On the rare occasions when we do take them to DQ I can’t have the one thing I long for, but the two trouser trophies weren’t around this time …

I was up and out the door in seconds; it wasn’t until I hit the drive-through that I realized I’d left my wallet at home. Not to be undone, I remembered the change drawer in my car (more dopamine at work, enhancing working memory to obtain the reward)48 and scrounged enough to pay for the tasty treat.

After annoying the teenager at the drive-through window with a handful of quarters, I parked with my Peanut Buster Parfait and commenced inhalation. Nights with Alice Cooper was on the radio; he played “Fire Woman” by the Cult. The song lasted longer than the dessert.

That day, I fell victim to a food cue—the damn TV commercial—that had an immediate effect, prompting me to go buy a specific product. But cues go way beyond that in how they affect eating behavior.


Your Brain on Food Cues

Cues aren’t just about the visual, like seeing the McDonald’s Golden Arches or watching a TV commercial. There are also a variety of sound cues—from corporate jingles to sizzling bacon49—and olfactory cues can be overwhelming50(but I find those Cinnabons never taste as good as they smell). Cueing can even be situational; if you eat in front of the TV or in your car, engaging in television watching and driving can create an unconscious cue to consume food.51

We’re eating all the time, and part of the reason is that we’re reminded to eat all the time.52 Food is big business, and that industry’s advertising budget is second only to the automotive industry’s. We have billboards, television, radio, magazines and newspapers, the Internet and mobile apps, sights and sounds and smells and a culture that is all about food, food and more food. Seriously, the next time you’re watching TV, pay attention to just how many of the commercials are for food.

“We’ve experienced that showing children food commercials stimulates eating behavior,” said Emma Boyland, an experimental psychology researcher at the University of Liverpool. “It also shifts their preferences toward types of food shown in the commercials.” It works on the category level, where McDonald’s commercials elicit higher fast food consumption. “Everybody responds to advertising,” she said. And yet kids don’t even know that they’re being persuaded.

And we don’t become immune to these cues either. “After repeated exposure to cues we don’t develop a resistance to them,” Boyland said. “Instead, we become more sensitive to them.”

And so we eat.



Out of Sight, but Not Out of mind

Those prone to overeating have a tendency to ignore the future consequences of doing so, such as weight gain. And studies have shown that people who have less self-control are more vulnerable to temptation when it comes to highly palatable food.53 Interestingly, these temptations don’t have to be in the form of actual food. The treats do not need to be readily available when the craving begins.54




What Exactly Is a Food Cue?

A cue is not food; it is a representation of food.55

“Food cues are about associative learning,” Eric Stice told me. “The more you pair Hershey’s Kisses with their tinfoil wrappers, the more tinfoil by itself will make you think of chocolate.” And it can be as subtle as a color. Think of the shade of purple that Cadbury uses for its Dairy Milk chocolate bars. Seeing a woman wearing a dress of that same shade can make you crave chocolate, and you don’t even know it’s happening.

It can even be a letter, like an M making you think of M&M candies, or, if someone wrote the letter in a way that looked like the Golden Arches symbol, of Big Macs. Toddlers can learn to recognize the letter M long before they learn their ABCs simply because they’ve been to McDonald’s enough times.56 That’s bad.

More often than not, however, cues are pictures of delicious food.57 DQ sundaes on a billboard. Skittles falling from the sky in a commercial. Steaming French fries in a magazine ad. Fresh doughnuts in a website image. I’ve posted photos of my barbecuing prowess on Twitter and Facebook. Last night I wanted to show how puffy my Yorkshire puddings were, and that went on Facebook too. I didn’t even stop to think about how I might be part of the problem.

Even restaurants are using images with increasing frequency. Margaret told me of a recent experience while dining out: the server brought an iPad to the table to show off pictures of the various desserts they had available. Items oozing chocolate, glistening with caramel, sprinkled with bits of toffee … Just writing about it makes me want them.

The point is that if you’re thinking about food, you’re going to want food. And we live in an environment where you’re forced to think about food.


The Effect of Cues on Appetite

The more sensitive you are to the rewarding effects of food, the more motivated you’ll be to seek it out,58 and the more motivated you are to seek it out, the more likely you are to eat it. And the more you follow through on these cravings, the more the pattern is reinforced.59

The issue with food cues is that over time you begin to pair the food reward with the signals and symbols (the cues) that express its location and availability.60

Remember all that dopamine stuff? It’s a key ingredient in this phenomenon.

            For our Stone Age ancestors, dopamine encoding of memory was valuable for remembering which pools and streams had the most fish, where to find the most nuts and berries and the migrating patterns of prey. But how is dopamine involved with seeing a picture of food?

It all links back to the effect on memory. When we see an image of tasty food, we are reminded of its rewarding effects, and this builds a greater sense of anticipation and desire for that feel-good sensation. Dopamine enhances this sense of anticipation further. Researchers call the effect the theory of incentive salience, which explains how those who are the most likely to crave food are also the most vulnerable to developing patterns of overeating.61

“It’s Pavlovian conditioning,” Carolyn Davis told me. “When Pavlov paired food with the bell, the dog learned to salivate just when the bell was rung even though no food was present.” Our cue-rich environment means the bell is always ringing, and it prompts us to action.

“The more you eat palatable food, the more your brain becomes hypervigilant to seek it out,” Stice told me. “If you regularly eat fried food, the smell of fried food will initiate a higher craving much more than in someone who doesn’t consume such foods.”

Incentive salience suggests that our motivation to obtain a reward is distinct from our sense of pleasure associated with that reward.62 Some people are more vulnerable to the rewarding effects of drugs not because they likethem more but rather because they want them more.63 This makes sense: while pretty much everyone likes chocolate, some people crave it.


Motivation Run Amok

A Dairy Queen commercial made me get in my car and drive three miles for a dessert. The cue motivated me to go. As we’ve noted, dopamine also played a role by making sure I knew not only where the DQ was located but also the fastest route to drive there.

The more people crave something, the more motivated they are to obtain it. It’s no longer simply a matter of food being present and engaging in opportunistic feeding (like the buffet); the cue itself prompts action. Plenty of us will go out on a chocolate or ice cream run to satisfy a craving. Often these cravings are the result of a cue, and the target doesn’t even realize that he or she has been manipulated. He thinks it’s just a random craving that popped up, but it wasn’t random at all.64

Interestingly, though, cues can have the opposite effect to the one intended. During the 1980s, Nancy Reagan, the US president’s wife, launched a popular “Just say no to drugs” campaign that used images of drug paraphernalia as part of its attempt to show the dangers of drug use. The problem was that the needles and crack pipes featured in advertisements and on billboards elicited a craving for drugs among users; incentive salience meant that such ads contributed to more drug-taking behavior, not less.65

And what can we say about a diet program or book that shows piles of sugary and high-fat foods—meaning to present them as something negative, or something to be avoided? Not surprisingly, such images can actually increasethe longing for those food items. The book Wheat Belly, by cardiologist William Davis (a book we do not recommend; you’ll learn why in chapter 5), has a stack of bagels on the cover. Davis unfairly demonizes wheat while simultaneously failing to understand that by having a pile of wheat products on the cover of his book he’s creating a longing for it in his readers every time they see it.


Breaking the Association: Training Your Brain

We’ll spend a lot of time in Stages II and III sharing ways in which you can counteract the conditioning that’s gotten you into this mess in the first place. Our Virtuous Cycle diet and fitness plan breaks it down step by step.

For now, understand that an important part of limiting your junk food intake will involve reducing exposure to the prompts that make you crave it. If you’re not being reminded of junk food, you’ll consume less of it. Logical, yes, but is it always practical? After all, you do have to live in this obesigenic world, where food cues are abundant. That’s why we’ll also work on strategies and skills for how to deal when you can’t avoid the prompts. Exercise is a big part of this. You’ll see why in chapter 4.

In the meantime, here’s one important bit of information: if you’re well fed, you’re less sensitive to food cues,66which is why you should make sure you’ve eaten before going to the grocery store. It makes that trip through the checkout line with all the chocolate bars and potato chips more tolerable. (Conversely, people who are hungry or have been on a restrictive diet for a prolonged period are more sensitive to cues.)67 One trick I use to avoid even looking at those treats is to read the headlines on gossip magazines instead; it allows me to feel superior.

But it goes beyond hungry versus full. Some people are more sensitive to cues. A 2012 study published in the journal Obesity used fMRI technology on 49 individuals and showed differences in brain reactions to food imagery between lean and obese subjects. The latter revealed much higher activation in the reward-sensitive areas of the brain when shown images of junk food. Interestingly, when images of bland foods were shown there was no difference in the brain activation between lean and obese subjects.68

And this is the part about this study that is going to blow you away. Pay close attention to what this means, because it’s damn important.

Those 49 people were in three groups: obese, normal weight and successful weight loss maintainers (SWL). The fMRI images of the SWLs showed greater activation in the frontal regions of the brain, which are responsible for future planning and decision making, when shown images of highly palatable food. This part of the brain is also responsible for “inhibitory control,” which means it’s a source of willpower when it comes to not acting on impulses, like the impulse to eat junk.

What this means is that these successful weight loss maintainers were using higher brain functions to think their way past the cue and not let it prompt them to desire food. They had trained their brains to defend against eating junk food.

And here is the killer point, which is a teaser for chapter 4: exercise strengthens the hell out of this region of the brain and its ability to function in this manner. The hell, I say!

If you begin to lose weight via dieting alone, the power of cues increases.69 We just mentioned that people who are hungry or dieting are more susceptible to the power of cues. Well, guess what? When you lose weight via a restricted diet combined with exercise, the effect of cues either remains the same or diminishes.70 This is why chapter 4 is going to be like a giant, gooshy Valentine’s Day love letter to exercise.


Your Brain on Alcohol

Before moving on to the bigger picture of a healthy lifestyle, let’s wrap up the brain science with a final topic.

Oh, and … hypocrisy alert!

I drink. Sometimes I drink too much. I’ve bailed out on more than one workout due to a hangover.

Okay. Now that that’s out of the way …

The Alleged Benefits of Alcohol Consumption
Moderate alcohol intake might be good for you, but studies extolling its virtues for preventing heart disease do not qualify as concrete proof. The studies are not controlled and randomized but instead rely on self-reporting of alcohol intake. What’s more, they often lump ex-drinkers (who are often people who have had a drinking problem in the past and can have a host of other bad habits) and lifetime non-drinkers into the same “abstainer” category.71

According to a 2005 study in Sports Medicine, “Available evidence suggests … moderate alcohol consumption may have favourable effects on blood coagulation and fibrinolysis [whatever that is—I think it’s good]; however, compelling experimental evidence is lacking to endorse this.”72

In short, when it comes to the question of whether alcohol can be good for your heart, the answer is, we’re 100 percent certain that we’re just not sure. However, we know for sure that what is good for your heart is exercise. Speaking of which …

The Effect of Alcohol on Exercise
When it comes to exercise, booze is not your friend. Have you ever tried exercising with a hangover? It’s no fun.
But it’s worse than that. According to the same 2005 study mentioned above, alcohol decreases athletic performance because it “adversely affects energy supply and impairs the metabolic processes during exercise.” Chronic use also causes muscle fiber wasting, and that’s bad too.73


The Calories! Oh, the Calories!
Booze has calories, lots and lots of calories:

Description Serving Size Approximate Number of Calories
Red or white wine 5 oz 120
Most beer 12 oz 150
Most spirits (no mix) 1 oz 65
Most liqueurs 1 oz 100


Alcohol calories rival that of sugar-sweetened beverages, which make up approximately 6 percent of Americans’ daily energy intake. A 2012 study of 11,000 US adults by the Centers for Disease Control and Prevention found that alcohol calories account for roughly 5 percent of total energy intake.74 Liquid calories are not satiating, and high ingestion is a major cause of weight gain.



Temporary Euphoria, Bad Calories

Earlier in this chapter, we explained how highly palatable foods give you a brief boost of euphoria; the mood-boosting effects of alcohol are more significant and do last longer, but the crash is harder too. A bad hangover is about as euphoric as a barf-coated shovel to the head.

It gets worse.
            According to a 2001 study in the American Journal of Clinical Nutrition, “increasing alcohol consumption was associated with a higher total energy intake.”75 That means more calories, but not just any calories—bad calories: more animal products and saturated fat and fewer vegetables.

“After a few beer the ability to make wise food decisions goes down,” said Richard Mattes, a professor of nutrition science at Purdue University. A number of other studies support the idea that alcohol has an appetite-stimulating effect, and can therefore lead to weight gain.76

So if you drink, you take in a bunch of alcohol calories and you’ve also got that “decreased inhibitions” thing going on. That same alcohol-infused behavior that causes you to French your co-worker at the office Christmas party is also what makes you think deep-fried cheese sticks will really hit the spot.

Okay, I know you’re going to have a difficult time accepting this, but I interviewed Jenni “JWoww” Farley of Jersey Shore fame (or is that infamy?) on the subject of how drinking can lead to grease inhalation.

“For season one of Jersey Shore all the partying led to lots of late-night snacking,” she told me. “Because of the alcohol I’d be eating pizza, Philly cheese steaks and cheese balls. Oh, God, I love cheese balls.” Tell me about it. “There were also days of being too hung over to go to the gym. After the first two seasons I hit a wall. I couldn’t fit into my pants anymore and I decided to clean up my diet a little and become more health-conscious.”

Cheesy cheese ball cliché alert! If JWoww can realize the booze is making her eat bad things and resolve to change, so can you. If you like the stuff, keep it moderate. Check out the sidebar on page XX for some tips on how.



Tips for Taking It Easy on the Ethanol


  • Do you really need to go to that party/bar/get-together? Only go to parties you actually want to attend.
  • Club soda is your friend; it looks just like a gin and tonic. No one will know.
  • Make your drink last. Don’t chug.
  • Delay drinking. Don’t reach for alcohol early in the evening; wait until the party or event is in full swing.
  • Drink water in between alcoholic drinks. You’ll imbibe less and be less dehydrated, which means a reduced hangover.
  • If you’re entertaining, ask people to take leftover booze home with them or find alternatives to give it away.




Skill Power More Than Willpower

Man, so much doom and gloom. You’re probably right freaked out by it all. Perhaps you’re thinking, How can I possibly find the will to resist this world of constant, overwhelming food and drink temptation? The answer is that resistance is more about building skills to navigate the modern food environment than relying on sheer determination and grit.

“Skill power is like riding a bike,” Dr. David Katz said. “At first it’s intimidating, but once you know how to ride it you wonder what all the fuss was about.” I’ll note that Katz is one of the sanest people I’ve spoken to on the subject of weight loss.

But what about willpower?

“There is far too great an emphasis on willpower.” Willpower is still an important component, Dr. Katz affirmed, but it’s not the be-all and end-all. “Everyone who wants to lose weight has the will to do so. Do today’s seven-year-olds have less willpower than the ones from 50 years ago? The obesity epidemic isn’t a result of a loss of willpower,” he said.

It’s pairing willpower with the necessary skills that makes exercise and healthy eating sustainable. “These things can happen by a force of will, but it’s difficult to sustain,” Katz said. Conversely, “When you have a skill you have it forever.”

Katz asserts the need for a “tool kit” for healthy living. He is also an accomplished carpenter. He explained that in order to build something, he needs both the appropriate tools from his shop, and the skills to know how to use them. Otherwise, that jigsaw could result in some missing fingers.

Make no mistake: there are tools needed to lose weight—things like guides to deciphering food labels and counting calories, as well as exercise equipment and workout clothes. But these need to be coupled with the knowledge of how to use them, not to mention a firm grasp on planning and time management. These, too, are important skills that make sustainable weight loss possible.

“Skill power paves the way,” Dr. Katz said.

When it comes to highly palatable food and its cues, it can seem as though your brain is your enemy, making you eat at an unconscious level, and that’s true. The trick is to become more conscious and use your higher cognitive capabilities to think your way through this—to use those “skill powers” that Dr. Katz describes to reduce the effect of cues.

This book is all about making you skilled at managing your weight. As you now should know, it goes far beyond the rudimentary mathematics of eat less, move more. These are skills for living, and you can master them. In Stages II and III, we’ll show you how.

We’re smarter than dogs. Just because the bell rings doesn’t mean we have to salivate.



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