Busting Diet Myths

The weight comes back, and yet we persist: For many of us, the beginning of the year is a time to reset our intentions, get in shape, and swear off unhealthy eating patterns, some of which can look a lot like…dieting. Traci Mann, Ph.D.—author of Secrets From the Eating Lab, and founder/director of the Mann Lab—explains that most diets have only temporary benefits, and that more often than not, we regain the weight. Mann has published numerous studies on the biology of weight loss, focusing on the effects that dieting has on the metabolism, as well as the psychology of willpower when it comes to dieting. Here, Mann reveals what happens to your body when you embark on an extreme diet, why you should ditch the scale, and how to achieve your “leanest livable weight.”

A Q&A with Traci Mann, Ph.D.

Why don’t diets work?

Weight regain is the most common result of dieting. Most dieters can lose weight in the short-term, but keeping it off is the exception to the rule. The majority of dieters regain the weight they lost within a couple years. The reason for this is that our bodies are set up to resist weight loss—they have no idea we want to lose weight. When we decrease our caloric intake by a lot, our bodies interpret it as the first sign that we are starting to starve to death, so they make a variety of adjustments that help us survive on less food.

“The majority of dieters regain the weight they lost within a couple years. The reason for this is that our bodies are set up to resist weight loss—they have no idea we want to lose weight.”

Our metabolism changes so that a little food goes a long way. With this drop in metabolic rate, if we eat the same amount of calories that used to lead to weight loss, we’ll find it no longer works. Our bodies are now running on fewer calories, and storing the leftovers as fat. The hormones that used to make us feel full change as well. The same amount of food that used to fill us up, may now leave us feeling hungry. There are also neurological changes that make it very hard to stay on a diet—a preoccupation with thoughts about food, increased focus on food, and feelings of unsatisfied hunger.

When it comes to dieting, what’s the actual role of willpower?

Willpower plays a much smaller role in dieting than people realize. Dieters don’t have less willpower than everyone else—hardly anyone has the willpower to withstand the brutal combination of all the changes I described above.

You might think it just takes one act of willpower to resist a cookie that’s on the table at your office, but it actually requires many, entirely separate acts of willpower. Unless your willpower is perfect—which is a tall order, and true only for a very small percentage of people—it won’t be enough.

Can focusing on willpower be harmful?

Aside from the changes described above, the main negative consequence of dieting is that most individuals regain the weight and then blame themselves for a lack of discipline—not realizing that what they’re experiencing is their bodies’ appropriate biological reaction to calorie deprivation.

What does “leanest livable weight” mean and how do you determine this number for yourself?

Your “leanest livable weight” is the weight at the low end of your “set range.” Your set range is a genetically determined range of weight that your body generally keeps you in, despite your efforts to escape it. If your weight is below that range, biological changes due to calorie deprivation happen, and generally push you back into your set range. However, if you stay within your set range—at the lower end of it—you should be able to maintain that weight without your body making those negative changes.

While there is no scientific formula to determine one’s set weight range, if you’ve noticed that your body keeps coming back to a certain weight, that’s generally around the middle of it. It’s likely around what you weigh when you are eating sensibly—without dieting or binge eating, and when you aren’t engaging in tons of exercise. For many of us, our leanest livable weight is heavier than our dream weight. I urge people to aim for their leanest livable weight, rather than below it. Embrace it—it’s where your body wants you to be, it’s easy to maintain, and you can be healthy there. Since this weight is within your set weight range—where your body tries to keep you—the only reason you would need to diet is if you’re currently well above that range. Otherwise, using sensible strategies should get and keep you there.

“For many of us, our leanest livable weight is heavier than our dream weight. I urge people to aim for their leanest livable weight, rather than below it. Embrace it—it’s where your body wants you to be, it’s easy to maintain, and you can be healthy there.”

What are some helpful strategies that you’ve found in the research that might be surprising/not well known?

In my book, Secrets From the Eating Lab, I set out twelve strategies to help you reach your leanest livable weight and stay there. My favorite is what I call “veggies first,” or “get alone with a vegetable.” If vegetables are not our first choice, and if they’re on our plate with other foods we like, we tend to ignore them. Vegetable vs. pasta, or vegetables vs. a burger, are not competitions that vegetables are likely to win. The contest a vegetable might win is vegetable vs. nothing.

That’s where this strategy comes along—before you put any other food on your plate—even before you prepare any other food (if you can swing this)—prepare and eat your vegetables. If they’re the only thing there and you’re hungry, you will eat them. This worked in research we did on school cafeterias, on my kids when they were little and hated vegetables, and it works on adults too.

Bigger picture, you talk about how weight is really beside the point—why is this?

You can be healthy at almost any weight—within your set range—so instead of focusing on the number, why not just focus on being healthy? Even better, it’s actually easier to improve your health than it is to lose weight. Consider this—studies of exercise routinely find that after starting an exercise program, people’s health improves (i.e, their heart rate and blood pressure) well before they any lose weight.

You did a study that showed a significant contributor to weight gain can be related to our coffee consumption. Can you explain that?

With all the talk about how unhealthy sugar-sweetened beverages are, we felt that coffee was getting ignored, and yet a lot of people have multiple cups of coffee per day—each loaded with cream and sugar. Reducing sugar from coffee is a good way to wipe out daily calories without making yourself feel hungrier.

We tested two ways to go about this. One way was to gradually reduce one’s sugar intake over the period of two weeks—each day a bit less sugar until there was no sugar in the coffee. Unfortunately, this didn’t really work. People who did this didn’t like the coffee as much each day, and once sugar was completely gone, they didn’t stick with drinking the black coffee.

However, our second strategy worked quite well: We trained people to drink their coffee mindfully—paying close attention to all the sensations of the experience, not just the taste of the coffee, but how the cup felt in their hand, the smell, how it feels in the throat, etc. In addition, we had a coffee professional (Tim Chapdelaine of Troupe Coffee) train people about five key features of coffee. (There are apparently many more features than five, but to keep it simple, we stuck with five.) The whole training took twenty minutes, and nearly all of the people who did it quickly learned to like their coffee without sugar, and continued to drink their coffee sugar-free for at least the next six months.

What is your lab currently working on? What about future studies?

My lab, the Health and Eating Lab at the University of Minnesota, is always up to something unusual. We studied comfort food to help NASA get astronauts to eat more, and to feel less stressed: We learned that comfort food doesn’t have any special abilities. Participants who ate comfort food, as well as those who did not, both felt better. Many rationalize eating comfort food to improve their mood, but we give comfort food credit for mood improvements that would have happened without it. You may as well save it for when you are happy and can really enjoy it.

We just completed a two-year study of people attending the eating extravaganza—that is the Minnesota State Fair, to see if they made healthy eating choices before attending (in anticipation of eating unhealthy at the fair). We called that “pre-compensation” (we made that word up) and sure enough, people do it. It helps keep your eating stable, despite the upheaval. We now recommend pre-compensation as a healthy eating strategy: If you know something unhealthy is coming up, be extra healthy a few days before.

“Many rationalize eating comfort food to improve their mood, but we give comfort food credit for mood improvements that would have happened without it. You may as well save it for when you are happy and can really enjoy it.”

Dieters often say that if there is unhealthy food in the room, they will notice it. We’re about to start a study looking at how quickly dieters perceive food in their surroundings, and if they’re more likely to notice it than non-dieters.

We will never stop trying to get people to eat their vegetables: We are starting a study to see if we can get middle school kids to eat vegetables, by getting the cool kids to eat them first, since kids this age are eager to do whatever the cool kids are doing.

The lab tends to operate on a shoestring budget to avoid the slightest appearance of a conflict of interest. We don’t take money from food or diet companies. The government doesn’t want anyone telling people to diet less, so they aren’t eager to fund us.

Traci Mann is a professor at the University of Minnesota, where she founded the Health and Eating Lab—otherwise known as the Mann Lab. She received her Ph.D. from Stanford University, and served as a professor at UCLA for nine years before moving to the University of Minnesota. She is the author of Secrets From the Eating Lab: The Science of Weight Loss, the Myth of Willpower, and Why You Should Never Diet Again. Mann has published many studies in scholarly journals, and continues to lead research focused on the psychology behind dieting, obesity, and self-control.

The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of goop, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.