Back in the 1960's, psychologists who were uncomfortable with the idea that overweight results just from eating too much began looking into other reasons of obesity. In 1961, a researcher named Paul Bruch proposed that obese people were unable to distinguish other bodily urges from hunger. An obese person in love, for example, might reach for the Pepperidge Farm Milano Cookies rather than making a date with his or her love interest.
This idea turned out to be wrong. However, Bruch and other researchers did learn that there were two common styles of eating that Bruch termed “restrained” and “unrestrained. ” Restrained eaters limited their food choices to a narrow list of foods. Unrestrained eaters could “eat anything.”
But Bruch and others found that restrained and unrestrained eating styles were not necessarily related to weight. Both obese and normal-weight people could have either restrained or unrestrained eating patterns. The underlying issue in obesity had to be something else.
Only in 1975 did psychologists Herman and Polivy propose that relative deprivation rather than obesity itself is the underlying cause of eating behaviors. People who eat a lot may get fat or they may not, researchers concluded. But people eat a lot when they feel deprived.
At this point, some researchers began looking for a hormonal or physiological explanation of the feeling of deprivation that leads to overeating. Some scientists developed a theory of biological weight. This was the idea that there is a certain weight we are programmed to reach and out appetites are driven, or dampened, so that we maintain it.
Other scientists developed a set point theory. This was the idea that the body naturally maintains weight at a set point, and that the set point rises when the body is threatened (as is the case with dieting). Other scientists began looking at the roles of hormones like adiponectin and leptin and insulin.
But another group of researchers looked at appetite in terms of psychological theory, reaching the conclusion that if you want to lose weight, the worst possible thing you can do is to diet.
The weight loss psychologists at first believed that simply restricting food intake in order to lose weight was a cue to overeat. Two researchers named Herman and Mack found that periods of restrained eating, that is, going on a low-calorie diet, were always interrupted by episodes of disinhibited eating, eating all you want of whatever food you wish.
These episodes can be described as binge eating or out of control eating. Herman and his collaborators concluded that going on a diet, any diet, was destined to cause ravenous cravings for food afterward. Dieting, Herman believed, would always lead to binge eating that would put back all the pounds and more. Or, as the leading diet (or actually anti-diet) book of the time said, Diets Don't Work.
Proponents of the “exercise only” school of weight loss use these ideas today. However, there turned out to be still more to the reality of intentional dieting and weight control. Diet researchers developed a more nuanced view of dieting in what was known as the “fat awareness” movement. Restrained eating of all foods, or “going on a diet,” was seen as a mindset separate from restrained eating of high-fat, highly palatable foods.
In the 1980's, researchers began to think it was the kind of food, specifically fatty food, that led to disinhibition of eating. In other words, people can resist food, except for fatty food. The idea arose that overweight people simply liked fatty foods more than normal-weight people.
The dominant explanation of overweight about 1990 was hyperpalatability theory, the idea that overweight and obese people somehow possess keener senses of taste for fat and sugar and the “mouth feel” of high-calorie food. The food industry responded, naturally, by hiring scores of chemists to develop flavor additives and texturizers to give low-calorie foods the same mouth feel as high-calorie foods.
But this doesn't seem to be the final explanation of the cause of overeating, either. By the early 2000's, researchers were learning that 30 years of diet propaganda had had an effect, that both normal weight and obese people held negative beliefs about high-fat foods.
Gaining weight through overeating was not just a matter of liking sugary and fatty foods more. Researchers finally came to the commonsense conclusion that just about everybody likes the taste of fat and sugar regardless of whether or not they are restrained about actually eating them.
In other words, people who are trying to lose weight by dieting don't have special difficulties controlling their consumption of fat and sugar. They don't have deeper cravings for high-calorie foods than people who don't attempt to restrain their eating, whether or not they are overweight. Eating high-fat foods doesn't trigger binge eating. Not eating high-fat foods doesn't trigger binge eating. In fact, researchers even found that they could trigger gorging and disinhibited eating simply by telling people they were eating high-calorie foods even when they were not. Weight loss psychologists theorized that restrained eaters impose artificial restrictions on the amounts of food they eat and the types of food they eat in order to conform to ideals chosen for them by others. If you have a I-gotta-be-me personality, you tend to overeat.
So what's the most important rule for breaking a habit of binge eating?
Don’t rely on willpower.
To lose weight, people need to eat less. They need to learn to ignore their body's signals to eat. As long as the choice is to eat less, rather than to eat nothing at all, the dieter has to exert cognitive control, or mental willpower, over what to eat, following rules, usually set by others, as to what to eat, how much to eat, and when to eat.
Weight loss dieters have to exert a huge about mental energy to stick to their diet plans. This approach simply does not work over the long term because people have a limited amount of mental energy they can use each day just as they have a limited amount of physical energy they can use each day. We all have more to do with our lives than just to diet.
There is only so much exercise you can do before you literally collapse from exhaustion. Competitive athletes, especially marathon runners, discover this principle for themselves when they “hit the wall.” There are famous videos of marathoners who have to crawl across the finish line on their hands and knees or who have to have teammates pick them up and carry them across the finish line.
The same phenomenon can happen to dieters, even to sedentary dieters. When people don't eat for several days (something I never recommend) or if they engage in long exercise sessions (3 or 4 hours or more) on an empty stomach (again, something I never recommend), their livers and their muscles literally run out of the sugar stored as glycogen in their muscles and their livers that their bodies need to keep moving.
It is relatively easy to understand how our bodies can drink their fuel tanks dry. But many of us overlook that our ability to do mental and emotional “exercise” has a daily limit, too. This draining of mental and emotional energy has come to be known as ego depletion, the draining of a mental reserve known as ego strength. Physical strength is defined by your ability to do exercise, but mental strength is defined by your ability to use your mind.
Both physical strength and mental strength are limited. Just as it can simply take too much physical energy to complete a marathon, it can take too much mental energy to stay on a diet. Navigating a complicated system of do's and don'ts is eventually more than ego strength can support. Any complicated diet is destined to fail. The problem is not that you lack willpower. The problem is that our bodies are designed to maintain our weight. The solution is to love your body as you feed it just enough to maintain your ideal weight. Don't fight your fat. What you resist persists. Give your fat mass just the right amount of care as you cultivate other interests in life. It may not shrink right away, but neither will you exhaust yourself trying to tame it.