Fermented cabbage probably doesn't fall at the top of your grocery list (because, to be honest, eating non-fermented cabbage is already a chore). But kimchi, a traditional Korean side dish, could be just what your gut needs.

Fermented foods contain probiotics -- good bacteria that live in our gut and play a large role in our bodies' immune function; they also impact our weight and our ability to lose weight, says Cimperman.

Studies have shown that eating a large breakfast full of protein makes you less likely to graze during the day -- but you already knew that, didn't you? What you don't know is that approximately two-thirds of Americans don't eat breakfast.

In Germany, 75 percent of people eat breakfast, and a normal morning meal consists of meats, cheese, soft-boiled eggs, fruit and bread -- plenty of fuel for the day ahead.

"Breakfast eaters are far less likely to be obese or overweight than non-breakfast eaters," says Cimperman. "Eating something in the morning helps get the body's metabolism going." But you have to do more than grab a Pop Tart (or two) on your way out the door. A study from the University of Missouri found that eating a high-protein breakfast can help reduce cravings for sugary food later in the day. It can also help regulate the brain chemical dopamine -- this can help you stop thinking of food as a reward.

For everyone saying that they don't have time for breakfast: Make time. "It doesn't need to be complicated," says Cimperman, who recommends eating a bowl of oatmeal with an ounce of walnuts and dried fruit; a banana with peanut butter or a smoothie made with Greek yogurt.

The average breakdown of the Mediterranean diet: 50 percent carbs, 20 percent protein and 30 percent fat. But they're eating predominately unsaturated fat from olive oil, olives and nuts -- not the unhealthy saturated and trans fats you find in pizza and processed foods. And here's the thing about saturated fat: studies have shown that it tricks you into eating more food, because it messes with your hunger hormones. On the flip side, unsaturated fats can help control insulin (the hormone that helps your body use sugar efficiently).

In addition to eating plenty of healthy fats, they get their carbs from whole grains and fruits, and their protein source is typically legumes and seafood. They do eat meat, but infrequently.