If you’re one of the many people hoping to shed a few pounds after the indulgent holiday season, here’s a bit of advice: don’t go on a diet.

Diets fail more often than they succeed — and usually for reasons outside of the dieters control.

Researchers Traci Mann, of the University of Minnesota, and A. Janet Tomiyama, of the University of California, have been studying the science of dieting for many years, and, as they explained in an article for CNN, diets fail more often than they succeed — and usually for reasons outside of the dieters control.

One reason for that is because it’s not a level playing field to begin with. No matter what you eat, your genetics determine your body shape. Naturally heavier people tend to need fewer calories than thin people to have enough energy to run on. That’s why heavy people can eat exactly the same number of calories as thin people, and have a store of fat left over.

Even if a dieter sees success at first, cutting back on calories can actually lead to physiological changes that make dieting less effective over time. In order to keep losing weight at the same rate, they have to reduce their caloric intake even more.

That’s particularly hard to do when you’re on a diet, Mann and Tomiyama explain, because dieting actually changes your brain chemistry, making food more noticeable than it was before — not to mention more delicious. Most dieters experience a bigger dopamine rush when they eat while on a diet than before, making that illicit chocolate chip cookie even more difficult to refuse.

As if dieters didn’t have enough working against them, it’s also really hard to stay full on a diet. That’s because dieting reduces levels of the “satiety” hormone, called leptin, which makes people feel full. Not only does dieting makes you feel hungry because you’re eating less — but it also makes you need even more food than you did before in order to feel full.

There’s really no way to win, except to admit that the dieting game is rigged. But before you throw in the towel completely, don’t forget that there are plenty of other positive changes that could be made to your diet that don’t have to do with losing weight — like eating more protein and omega-3s.