There's at least one pretty obvious reason most diets are doomed to fail -- they're not exactly fun.
But this explanation doesn't give a complete picture of just how difficult it is to drop weight. For example, why does someone with the willpower to stick to a strict diet lose half her bodyweight, while someone else on the same eating plan actually gains weight?
The answer, like most things in life, is complicated, which is why obesity specialists are starting to look at obesity not as one single problem, but as a cluster of diseases -- in much the same way doctors view cancer, according to The New York Times.
There could be dozens of types of obesity
Dr. Lee Kaplan, director of the Obesity, Metabolism & Nutrition Institute at Massachusetts General Hospital, told the Times that he estimates there could be up to 59 different types of obesity. Fifty-nine! So what's good for treating one form of obesity may not work for another, and even if you find a treatment that works for many types of obesity, there's a pretty good chance you won't cure all of them.
An analogy to cancer is a useful way to think about it: You wouldn't remove the breasts of someone with lung cancer. Unless you were a terrible surgeon who somehow was allowed through medical school without a basic understanding of anatomy.
There are also more than 30 genes that may play a role in obesity, though it's still difficult to isolate exactly which genetic and environmental factors are most relevant. What's still poorly understood, though, is how exactly these genes interact with each other and the environment to cause obesity. And if you can't isolate the cause, a cure becomes even more difficult.
Knowing your family history helps, but it's certainly not your destiny. "While having obese parents or family members does not predestine anyone to be overweight, knowing that your genes may be particularly sensitive to foods high in sugar and saturated fat content will help you to understand your individual needs," says Dr. Caroline Apovian, director of Nutrition and Weight Management at Boston Medical Center. "Those of us with the genes that predispose us to weight gain will gain weight in an environment with plentiful, cheap, unhealthy foods."
You'll probably have to take a trial-and-error approach
While the general pillars of weight loss hold true -- eat healthy, exercise often, get enough sleep -- in what amounts, and what "eat healthy" means specifically, can vary from person to person. Unfortunately, treatment is usually relegated to a trial-and-error process, until people can find out exactly what will work for them in terms of weight loss.
Dr. Kaplan, for example, told The New York Times he has 40 different therapies he tries with obese patients, including different diets, aerobic exercise, sleep enhancements, and more than a dozen drugs.
And even if someone initially loses weight, being able to keep it off is key. Most people who lose weight will gain it back, making a comprehensive treatment for obesity that much more difficult.
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