Eat Less, Weigh More
If you sometimes feel that dieting has surpassed baseball as the national pastime, you’re not alone. So many of us are dieting, coming off a diet, or feeling guilty that we’re
not
dieting, that the word “diet” has morphed from a noun to a verb.
Yet here’s the thing: Not one study has ever shown that diets produce long-term weight loss for any but a tiny number of dieters. Not one.
Consider the Women’s Health Initiative, the largest, longest, and most expensive randomized, controlled dietary intervention clinical trial, designed to test whether the prevailing wisdom actually works. More than 20,000 women tried out a low-fat diet, reportedly reducing their calorie intake by an average of 360 calories per day. After almost eight years on this diet, there was no change in weight from starting point, and their average waist circumference, which is a measure of abdominal fat, had
increased
!
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Consistent with the research conducted on thousands of other diets, including my own study, the dieters lost weight at the beginning, but gained it back.
Commentators often attribute weight regain to people’s inability to maintain their diets over the long run: the old “no willpower” problem. Yet this study was well controlled to support the women in maintaining their diets.
Weight regain occurred despite maintaining their reduced-calorie diet!
And lest you think these results are particular to low-fat dieting, check out the data from this study of other popular diets.
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After twelve months, Atkins dieters were eating 289 fewer calories compared to when they started the diet, Zone dieters were eating 381 fewer calories, LEARN dieters were eating 271 fewer calories, and Ornish dieters were eating 345 fewer calories. Yet all were steadily regaining weight over the last six months of the first year. And this despite an accompanying increase in exercise!
Imagine this: You spend eight years denying yourself foods, feeling virtuous as you successfully restrict yourself—all that pain and discomfort—and, at least from the perspective of weight, nothing to show! Wouldn’t you rather have been among the 29,000 women in the control group of the Women’s Health Initiative who were encouraged to continue their usual eating habits? They didn’t lose weight either, but at least they didn’t endure the misery of dieting!
It’s not just that dieting doesn’t work. Diet enough and it may actually push your setpoint up, so you wind up weighing more after the diet than if you’d never started the darn thing to begin with!
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Dieting interferes with your weight regulation system in several ways.
Recall our discussion of the hormone leptin from chapter 1. When you diet, your body produces less of this appetite-suppressing hormone.
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This, in turn, jump-starts your appetite, making that chocolate cake look as tempting as a stack of unattended $100 bills. No wonder you want to break your diet! Leptin also slows your metabolism. Combine the two and you find yourself on the Weight Gain Express.
But that’s not all. Over time, as you diet, stop dieting, diet, stop dieting, your body gets sick of it all and simply sets the leptin-meter to permanent low, producing less of the hormone regardless of which part of the diet cycle you’re in.
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Less leptin means your body isn’t working as effectively as it should to tame your appetite and stoke your metabolic machinery. Your setpoint has now been pumped up a notch.
In addition to the reduced leptin during diets, your body pumps out
higher
levels of lipoprotein lipase, an enzyme that increases fat storage.
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And, if the studies in rats translate to humans (and there is strong evidence they do), yo-yo dieters are compelled to choose foods higher in fat.
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Some reward for trying to be “good,” huh?
So here’s a review of the above, with a few other choice tidbits added in. Dieting:
• Slows the rate at which your body burns calories.
• Increases your body’s efficiency at wringing every possible calorie out of the food you do eat so you digest food faster and get hungrier quicker.
• Causes you to crave high-fat foods.
• Increases your appetite.
• Reduces your energy levels (so even if you could burn more calories through physical activity you don’t want to).
• Lowers your body temperature so you’re using less energy (and are always cold).
• Reduces your ability to feel “hungry” and “full,” making it easier to confuse hunger with emotional needs.
• Reduces your total amount of muscle tissue (and you may know that a pound of muscle burns more calories than a pound of fat).
• Increases fat-storage enzymes and decreases fat-release enzymes.
The message here? Don’t blame yourself when you “break” your diet. It’s not about gluttony or a failure of willpower. In fact, most dieters show extraordinary self-restraint, persistence, determination, and willpower. You didn’t fail; the diet did.
Numerous animal studies verify this simple fact: After a diet, an animal will regain the weight
without overeating
. Reflect on your own history: how much were you really eating when you regained the weight?
The first step toward recovery: Do no more damage. In other words, quit the diet habit cold turkey. Since most dieters are likely to be above their setpoints, simply kicking the diet habit and restoring control to your body may result in a bit of weight loss. But regardless of whether your weight changes, I do promise that there’s even better stuff in store for you.
Sounds too good to be true, doesn’t it? No more cutting calories and going hungry. No more guilt about what you eat. All you need to do is lighten up and put your body in charge. Well, perhaps there’s a little more to it than that. After all, it’s been a long time since you trusted your body, and, like any damaged relationship, it will take a while to begin communicating clearly again. Chapter 9 guides you in becoming attuned.
Of course, diet attempts are not the only contributor to your weight. Plenty of other lifestyle behaviors and environmental exposures affect that number on the scale: activity habits, stress, even the toxins we’re exposed to. Let’s tackle the “activity makes you skinny” assumption next.
The Couch Potato Syndrome
Though more people are acknowledging that diets don’t work, there is rarely any challenge to the concept that exercise can produce weight loss. We hold very tenaciously to our beliefs that “fat = lazy” and “if people would just get off their butts and get moving, they’d be much thinner.” The problem with these ideas? There’s no evidence to support them!
In theory, exercise should help moderate your setpoint. Physical activity (whether in the gym or in the garden) increases your sensitivity to signals of hunger and fullness
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by increasing leptin sensitivity
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and production, increasing insulin sensitivity, and affecting numerous other hormones, neurotransmitters, and cellular receptors involved in weight regulation.
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In fact, burning calories is just a tiny part of the many ways physical activity affects your weight. Check out the different ways physical activity can rev up your metabolism and affect your weight. It:
• Speeds up your metabolic rate, not just while moving /exercising, but for many hours afterward.
• Reduces your hunger drive.
• Increases your body temperature so you burn more energy.
• Increases your energy levels so you burn more energy.
• Improves your sensitivity to hunger and fullness.
• Increases your amount of muscle tissue so you burn more energy.
• Increases fat-burning enzymes and decreases fat-storing enzymes.
• Improves cell sensitivity to insulin (you need less to do the same job), allowing you to burn more energy.
• Uses more fat and less carbohydrates for energy (which helps stabilize blood glucose levels).
Last—and maybe least important—is that while doing many of these, it burns calories.
Given all these dramatic effects, will a dedicated exercise routine help you to lose weight, or more precisely, body fat? The answer may surprise you.
Exercise Is Not the Ultimate Weight-Loss Panacea!
Contrary to popular belief and despite the exercise effects listed above, long-term studies do
not
show that people lose significant weight on exercise programs.
Before we examine this, first note that weight differences between those who exercise regularly and those who don’t aren’t very dramatic. Most studies find that people who regularly exercise are only about five to ten pounds lighter than those who are sedentary. The Women’s Health Study, for example, evaluated almost 40,000 women and determined that the difference in body mass index between those at the highest level of exercise and the lowest was only about 0.4. For a 5’4” woman, that amounts to about three pounds!
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The Harvard Alumni Study compared more than 12,000 men who regularly participated in various intensities of exercise and, similarly, found a difference of less than five pounds.
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These results are consistent with many other studies.
Since good health habits tend to travel in packs, it’s difficult to definitively attribute even these slightly lower weights to exercise. The same people who exercise may also eat their leafy green vegetables, have better stress management techniques, or maintain other habits that may explain some or all of the weight difference. Also, perhaps the causality operates in the other direction; after all, heavier people may be less inclined to exercise given the lack of social support. Gyms, for example, are rarely friendly to those in larger bodies. And comfortable exercise clothing is harder to come by if you’ve got a larger body.
But what happens when people try to lose weight through exercise? When formerly sedentary people regularly participate in exercise programs, the research is not showing dramatic weight loss. In fact, a meta-analysis of twenty-five years of exercise programs indicated that training programs only result in loss of 0.2 pounds per week.
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Consider the Heritage Family Study as an example, in which 500 men and women participated in a twenty-week endurance training program.
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On average, the men lost less than a pound, and the women lost nearly nothing! In another study, the large women participating in an intense six-month resistance training program also did not exhibit any body fat loss or change in body composition.
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The Midwest Exercise Trial put men and women on a sixteen-month intensive endurance exercise program.
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The men were quite successful, losing, on average, about 11 pounds; the women, on the other hand,
gained
a little over a pound, while losing less than a half pound of body fat!
Surprisingly, many studies have found women actually
gain
weight and body fat with exercise. One study that monitored large women who did six months of aerobic exercise four to five times a week found that a third of them gained 15 pounds of body fat, and that the gainers averaged an 8-pound weight gain.
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If exercise affects so many aspects of your setpoint mechanism, you may be wondering, why hasn’t it proven to support weight loss? No one has the answer to this question, but I suspect there are two explanations. The first relates to the point raised earlier that your body is very protective at making sure you don’t lose too much weight, but is relatively lax about supporting weight loss. Consider our discussion of leptin. Remember that you reach a saturation point where more leptin doesn’t have a correspondingly stronger effect? This fact suggests that exercise (which helps you produce more leptin and improves leptin sensitivity) is very effective at preventing weight gain, even if it is less effective at promoting weight loss, and could explain why people who exercise regularly are just a little lighter than those who don’t.