Why Is It So Hard To Lose Weight?

Soda is displayed in a market in the Brooklyn borough of New York City. The US government Tuesday removed the artificial sweetener saccharin, long believed to be a potential cancer-causing substance found in diet drinks and chewing gum, from its list of hazardous substances.

Photo Credit: AFP/Getty Images/File - Spencer Platt

You've almost certainly heard the chorus of offensive myths and falsehoods about overweight people. Every time I write about weight management and food politics, it's guaranteed that someone will start railing about how fat people are fat because of their own laziness, poor self-control, lack of discipline, etc. And it's all over popular culture. According to these folks, trying to address obesity as a public health issue, by changing public policy about agriculture subsidies and food labeling and school lunch programs and city planning and so on... it's a waste of time. Worse than a waste of time, even: it's the nanny state run amok, coddling people who won't take care of themselves, treating people as if they had no personal responsibility for the consequences of their actions.

There's just one little problem with this notion: There's no good reason to think it's true.

Actually, there are lots of things wrong with this notion. It's grossly bigoted and insulting, for starters. And it does absolutely nothing to address the situation. If you genuinely think obesity is a health problem that people ought to do something about... telling people that they're lazy slobs who just need to straighten up and fly right isn't exactly being part of the solution. In fact, it may even be part of the problem.

But mostly, there's just no good reason to think it's true. Rates of obesity have been going up dramatically in the last few decades. And they typically go up whenever a modern American diet gets introduced to a culture. Does it really make sense to think that human psychology and human nature has radically changed in the last few decades: that as a species, we've somehow evolved to be lazier and less self-disciplined in just a few generations? Or that the introduction of a modern American diet somehow magically zaps the willpower center of the human brain?

And if human nature hasn't changed that radically in a few generations, but human bodies have... doesn't it make more sense to think that something else has changed? Something about the food environment we live in? Something about our culture, our economy, our public policy... and the way these things interact with human physiology and psychology? Something about high- calorie processed food being easily and cheaply available on every street corner? Physical education getting pared to the bone in public schools? Our government subsidizing high-calorie/ low- nutrition food? Food ads on TV approximately every six nanoseconds?

This is a huge topic, and it's not one I can even come close to completely covering in one article. And I should spell out right now: I am not an expert in this field. I am not a nutritionist, or a physiologist, or an economist, or a researcher on weight loss. What I am is a smart, reasonably well- read lay person who's done extensive reading about both weight management and food politics. And I'm a person who has personally lost a significant amount of weight and who therefore knows, first- hand, many of the things that make weight management easier, and many of the things that make it harder.

I'm going to break those things down into four broad categories: money, public policy, corporate greed, and evolutionary hard-wiring, all of which are intricately interwoven.

Physiology and evolution.

When it comes to food and hunger, here's the first thing you have to remember: Human appetites and instincts about food evolved about 100,000 years ago on the African savannah, in an environment of food scarcity and intense food competition. For that matter, we're descended from hundreds of millions of years' worth of pre-human ancestors, who also lived in environments of food scarcity, intense food competition, or both.

And as a result, we have some very powerful, deeply ingrained instincts about food. We are hard-wired by evolution to get hungry whenever we see food. We are hard-wired by evolution to eat whatever food is in front of us. We are hard-wired by evolution to keep eating, to eat as much of what's in front of us as we can without bursting. We are hard-wired by evolution to want high-calorie foods, rich in fat and sugar. We are hard-wired by evolution to conserve our energy, and not expend any more of it than we really need to.