7 Biggest Diet Myths

While going too long without eating can set you up for diet catastrophes, "grazing can also rack up calories," Lippert said. Handful after handful of almonds, or continuous sips of banana-soy smoothies, will eventually appear on your waistline, she said.

A grazing habit degrades a person's internal guidance about when to eat, making it nearly impossible to tap into hunger and satiety cues, Lippert said. "If you can't remember the last time you were really hungry, that is not a good thing," she said.

When we eat freely and continuously, in any place at anytime, we begin eating more for stimulation and reward, rather than responding to our bodies' needs, said Dr. David Kessler, former FDA commissioner and author of "The End of Overeating; Taking Control of the Insatiable American Appetite" (Rodale Books, 2009).

Such behavior is not good for anyone's diet.

Saturated fat causes cellulite, and it's bad for you anyway.

Cellulite is no different than other body fat; some fat just gets stored as cellulite in some parts of the body. And any excess body fat is caused by excess calories, no matter whether those calories come from bacon, donuts or carrot sticks.

Past studies lumped saturated fat in with trans fat, giving the former a bad rap by association. But while trans fat is truly evil, saturated fat found mostly in animal products performs many critical functions, such as helping the body use calcium and omega 3s, boosting the immune system and protecting major organs from disease.

And, in small quantities, it can even help your diet. "You can blow through half a block of low-fat cheese, because it doesn't taste like anything," Lippert said. "But have a little full-fat cheese, and magically you are satisfied."

Rather than shunning saturated fat, scientists suggest the best eaters limit it to about 20 grams a day, a third of the recommended total fat intake. A small burger (3.5 ounces, 75 percent lean meat) has about seven grams of saturated fat, as does a pat of butter.

You can eat whatever you want, as long as you exercise.