Is your stomach growling hours before lunchtime? You might need more protein for breakfast. In a recent study, researchers at the University of Kansas and Purdue University fed volunteers a diet in which they got either 18 to 25 percent of their calories from protein or 11 to 14 percent, an amount closer to what people typically consume. Those who started the day with extra protein reported feeling fuller longer than those who got more protein at lunch or dinner. High-protein foods include lean meats, eggs, low-fat dairy products, and fortified foods.

Read more on how to boost your energy and read our report on protein bars.