Do you hit an afternoon slump every day? Are you feeling drained despite getting enough sleep? Take a look at your food.

In general, healthy foods like fruits, vegetables and whole grains will keep your energy levels higher than processed or junk foods. But there are some ways you can use those good foods to boost your energy even more:

•  Eat enough calories. Very strict diets can zap your energy if you’re not eating enough. Healthy weight loss should not exceed one to two pounds per week. If you’re losing much more than that, you may feel tired and could be skipping important nutrients. Women should eat at least 1,200 calories and men should eat at least 1,500 calories per day.

•  Avoid candy and sugary treats. These foods may give you a quick boost of energy, but your body will quickly process the sugar. Then, you’ll feel more tired than before.

•  Eat between meals. Many people find they need small snacks throughout the day to keep their energy up. Keep the snacks small and light, such as a small serving of nuts or fruit.

•  Drink water. Even mild dehydration can make you tired. Aim for eight glasses of water per day. You may need more if you're exercising or sweating.

•  Don’t overeat during meals. Do you ever feel like taking a nap after a big lunch? Avoid this by eating a moderate sized meal, and stopping when you start to feel full.

•  Don’t rely on “energy bars.” Many of these bars contain as much sugar as a dessert, as well as processed ingredients. Instead, opt for food with protein, healthy fats and whole grains to keep you satisfied.

Source: Harvard Medical School and Centers for Disease Control and Prevention