If you want to shrink your gut, get enough protein in your diet. In this case, about 25 percent of calories. Why? For starters, protein makes you feel full and helps you build muscle (which increases metabolism, thereby making it easier to lose weight). Just as important, high-protein diets have been shown to be the best way of attacking belly fat. In one study, published in the International Journal of Obesity, Danish researchers put 65 people on either a 12 percent protein diet or a 25 percent protein diet. The low-protein dieters lost an average of 11 pounds, which isn't bad. But the high-protein subjects lost an average of 20 pounds--including twice as much abdominal fat as the low-protein group.
If you're among the 30% of Americans who sleep less than six hours a night, here's one simple way to whittle your waistline: catch more Zs. A 16-year study of almost 70,000 women found that those who slept five hours or less a night were 30% more likely to gain 30 or more pounds than those who slept 7 hours. The National Institutes of Health suggest adults sleep seven to eight hours a night.
This may explain why the fat-burning effects of eating more protein were confirmed in a study published in the American Journal of Physiology. One group was fed a high-protein diet (just over 1 gram per pound of body weight per day) while the second group consumed an amount closer to the lower recommendation of the RDA (recommended dietary allowance). The group eating the higher-protein diet burned the most fat.