The title of this post comes from a book I’m currently reading for research called Secrets From the Eating Lab, by Traci Mann. It’s made me rethink (and in some cases, reconfirm) pretty much everything I believe or at least was led to believe about weight, obesity, and dieting. She starts off telling us that diets don’t work, and as much as that may sound disappointing, let’s just think about it for a minute. She’s right. They don’t. Weight Watchers for example has a 16% success rate. What other industry can boast an 84% failure rate and still call itself successful? The diet industry, that’s who. Their entire business model is predicated on us being humans.
What does that mean? Well, as Mann states there are several factors why diets fail. What the diet industry wants you to believe is that the diet failed because you failed. You weren’t disciplined enough, you didn’t follow the rules, you cheated, you’re bad, bad, bad. That’s, and please excuse my French, bullshit. Diets fail, says Mann because of these three important reasons:
1. Biology: Genetics plays a huge role in our weight and we’re born with a blueprint for basically the weight that our bodies are meant to be. Your body stays in what Mann calls the “set weight range” most of your adult life. If your weight strays outside of it, on either side by about 15 pounds, give or take, your body works hard to get you back to it. She cites evidence from research that studied not only adopted children, but also studies of 93 sets of twins who were separated at birth and grew up in different environments. What they found is that it was biology, not how they were raised, that determined their weight.
Hormones are another biological reason that diets don’t work. As you diet and lose weight, says Mann, you lose body fat, an active part of your endocrine system, producing hormones that are involved in the sensations of hunger or fullness. As you lose fat, the levels of hormones that help you feel full decrease, while the hormones that make you feel hungry increase. These changes in hormone levels were still detectable in people a year after they stopped dieting.
The other biological reason, and one a lot of us have heard before, is that our metabolism “betrays” us. Actually, it’s just doing its job. Our ancestors, the ones who survived to pass along their genes and help us evolve into “us”, were successful at surviving during times of deprivation. They did this by being extremely efficient with the calories that came in and storing anything spare for those lean days. When you’re restricting your calories, your body makes it a priority to store them as fat, even if your intake contains no fat. Don’t be mad. Your body just doesn’t want to die of starvation.
Interestingly, she notes that a person who diets themselves down to 150 pounds, is physiologically different than a person who already is 150 pounds. The dieter has to always eat fewer calories than the non-dieter of the same weight. They also must eat fewer calories per day than they did to get to that weight in the first place.
2. Psychology: Any one who has been on a diet knows that the second you’re told that you can’t have something, you kind of really, really, really want it. A famous study by Ancel Keyes in the 1940s took thirty-six men and fed them a 1,600 calories a day diet. This wasn’t starvation, but it was roughly half of the calories these men were used to eating. As the experiment went on, these men lost interest in everything, all they could do was obsess about food. They talked only about food, collected cook books, cut out recipes, became quite surly and introverted, and engaged in other anti-social behaviours.
From an evolutionary point of view, this is useful behaviour. People who focus solely on food would be the ones to actively seek out food, forage, hunt, gather, whatever was necessary to stay alive. Again, it’s really hard to fight human nature and our will to live.
Mann conducted a study along the same lines in which they examined people who were denied a particular kind of food. They had the participants record how many times a day they ate a certain kind of food, then told them that they had to go a week without eating it. They were then told to record how many times they thought about that food. It was a lot. She points out the earliest story of Eve and the apple. We are predisposed to want the forbidden fruit.
3. Stress: Stress is not the bad word that we’re always told to believe. It’s a quite useful response to situations in which we have to flee a predator. The problem today is that there aren’t a lot of sabre toothed tigers around, just jobs, mortgages, kids, co-workers, cost of living, Donald Trump, etc. Stress causes a hormone to be released called cortisol. I’m sure you’ve heard of it. Cortisol is released during a stressful incident and floods your blood with glucose so that you can flee the tiger. The problem is that our stress today is chronic, not episodic. We don’t run or climb a big tree and thus rid our bodies of the extra glucose. We store it as fat on our bellies specifically. And belly fat is the kind of fat that has been linked to cardio-vascular disease.
The other thing that stress does is it changes our behaviour. When stressed we overeat (think “stress eating”), we don’t exercise as much, and we sleep less. Sleep-deprivation actually leads to overeating because the part of our brain that controls impulse is inhibited and the part of our brain that motivates eating is enhanced.
Just to make things worse, dieting itself is a stressful act. Deprivation and monitoring of food, having to say no to people’s generosity when they offer you something that is forbidden, all contribute to elevated cortisol levels in study participants. Most significantly it was the act of deprivation more than the monitoring that did so.
The diet industry is like a gigantic vulture, circling above us, sniffing out our insecurities and our foolish human desire for a magic bullet that will transform us into photo-shopped super models. We must strive, as Mann says, to eat in a way that allows us to be our lowest lean weight without dieting, and a huge, huge part of this is acceptance and love of our bodies. So much brainwashing to undo. So many magazines to burn. And a $60 billion a year industry to ignore.
There’s much more to this book, and some really enraging points raised by Mann, but this post has gone on too long already. Stay tuned for Part II: Fight the Power.