The direct cause of obesity is simply long-term caloric surplus. When people consume more calories than they expend, the extra energy is stored as fat in adipose tissue. When caloric surplus continues for long periods of time, it causes adiposity and weight gain to such a degree that health and activity are compromised.
Given the simplicity of calorie balance, treatment of obesity should involve nothing more complicated than eating less, exercising more or both. Indeed these strategies work if employed to sufficient degree. For example, people who eat very low calorie diets always lose weight.
So what's the problem? If people know that all they have to do to lose weight is eat a little less and do some exercise, why are there so many obese people and why do their ranks continue to grow every year? Have they not been educated about calories? Are they stupid? Are they lazy? Are they gluttons?
Many naturally thin people think so. They assume their physiques are a result of simple self-discipline; and they are fond of lecturing obese people on how "easy" weight control really is if one simply applies a little "willpower".
The odd thing is that obese people actually appear to have a great deal of willpower. Many of them have achieved great success in other areas of life. Furthermore, time and again, studies of eating habits show that overweight people actually eat LESS than most naturally thin people. Are these studies simply wrong?
The problems of obesity are hunger and metabolism not education, stupidity, laziness or gluttony. Obesity occurs as a result of alterations in appetite regulation and metabolic heat production that are in turn influenced by culture, dietary customs, socioeconomic status and scores of other factors. Whether the underlying abnormalities of appetite and metabolism have a common cause and whether that cause is the same for all obese people is unknown. Is obesity actually just a sign or symptom of an underlying disease rather a disease itself?
Obesity is usually considered a symptom of overeating and inactivity. In other words, most people believe that poor food choices and sloth CAUSE obesity.
I think that this view is tragically short sighted.
The truth is that overeating and under-burning are merely "proximal causes" and that they themselves are symptoms of a much deeper and hidden agency. Let me use an example to clarify this:
When a person deliberately jumps off a building and dies by suicide, we don't say that "he died because he hit the ground at a high speed". We say that he died because he jumped and he jumped because he was depressed and he was depressed because of a chemical imbalance in the brain that was in turn caused by genetics (or by tragedy or something). Thus we would say that the PROXIMAL cause of the man's death is blunt trauma from hitting the Earth at a high speed, but the ultimate cause of his death was a chemical issue in the brain. In other words, a long sequences of causes and effects led to the ultimate death of the man.
But when it comes to weight, we blame the proximal cause; we say that poor eating and exercise habits are the "cause" of obesity. This really is no different than telling the family of the man who jumped that "he died because he hit the ground".
So what we SHOULD be looking for with obesity are the ultimate causes and not just the obvious proximal causes. In fairness, many scientists and doctors share my view and are indeed examining obesity much more deeply. We are starting to understand what REALLY causes obesity and what we are learning is fascinating and shocking.
Do people really have control over how much food they consume?
Is it just a choice?
You might say "Sure. I can choose not to eat too much." And you can likely prove yourself right by "pushing away from the table" tonight at dinner and going to bed just a little bit hungry.
Can you do the same thing again tomorrow? Probably. But can you do it every day for a week, a month, the rest of your life?
I'll wager that you can't. I certainly cannot. For most of us, a couple of days or weeks of hunger is about all we can stand and then, despite our best intentions and our strongest willpower, we find ourselves eating, almost without control.
Hunger or appetite is a basic human survival urge. It is an urge that builds more slowly than others but is fundamentally no different than pain that makes us pull our hand away from a hot burner and no different than breathing. In fact, let's compare hunger and breathing; they are really very similar.
Breathing is the urge that keeps us supplied with oxygen which we need in order to run metabolism in every cell in our body. If the brain runs out of oxygen for longer than three to four minutes, it starts to rapidly die, so our need for oxygen is always urgent. Because the need is urgent, so is the drive to breathe. This means that we quickly begin to suffer intensely if we stop breathing.
Now, let's say that I challenge you to stop breathing for thirty seconds. Can you do it? Probably.
What about a minute? Again, with practice, probably.
Now let's say that I ask you to hold your breath for four minutes. Chances are good that you'll tell me to go jump in a lake. But let's say that I up the ante. Say that I offer you a million dollars to hold your breath for four minutes. Or a billion dollars…
Can you do it?
No you cannot. Nobody can. No matter how much you want the billion dollars, the survival urge of breathing will win and you won't get the money.
Now let's consider again the survival urge of hunger. Can you go hungry--not starved even, just hungry-- every day for five years?
Absolutely not. Nobody can. The survival urge of hunger will win.
Survival urges are far stronger than free-will. They cannot be confronted head-on.
"But wait a minute" you might say. "Holding my breath too long will kill me, but eating less food every day won't. In fact, Doctor Holland, as you should know, eating less every day will actually help me because I am overweight!"
And you would be right. But here's the problem: your body doesn't "KNOW" that it's too heavy right now. It "thinks" that your weight is perfect just like it is and every time you start to lose weight by eating less, it reacts to that as if you are about to starve to death. Your body reacts to weight loss by making you hungry and the more you lose and the longer you do it, the more hungry you get. Something or things is/are "fooling" your body into keeping you fat.
So, even though you need to lose some weight, your body will fight caloric restriction as if it were dying of starvation. You'll never win that battle.
Does that mean that permanent weight-loss is hopeless?
It means that instead of fighting your body's urge to eat directly, we need to turn-down that urge, to "re-educate" your body so that it no longer "believes" that overweight is healthy and healthy-weight is starvation.
Before I explain HOW to accomplish this task, I need to introduce a concept called "set-point".