If you often feel sluggish during the course of the day, you may want to take a closer look at the breakfasts and lunches you're eating. If they are large and contain a lot of fat, you may want to rethink your menu.

The reason is quite simple. The body takes longer to digest dietary fat than other food components. Likewise, the larger a meal is, the more energy is needed for digestion. And if the body expends a good deal of energy on digesting your food, there's less energy available for the things you need to do -- think, work, exercise, and so on.

One highly recommended strategy: Small, frequent meals that contain low-fat sources of protein with complex carbohydrates. By eating small meals every 2 to 3 hours (instead of the time-honored "three square meals"), you'll keep your energy at a steady level.