Eat For Energy - Boosting Your Natural Energy: Chronic Fatigue

Content provided by the Faculty of the Harvard Medical School

Eat for energy

The tried-and-true advice for healthful eating also applies to keeping your energy level high: Eat a balanced diet that includes a variety of carbohydrates, proteins, and fats with an emphasis on vegetables, whole grains, and healthy oils. Taking a daily multivitamin will ensure that you get the vitamins and minerals you need, but taking extra amounts of individual nutrients won't give you more energy.

In addition, eating certain types of foods in particular amounts can help prevent fatigue. Because different kinds of foods are converted to energy at different rates, some — such as candy and other sim­ple sugars — can give you a quick lift, while others­ — such as whole grains and healthy unsaturated fats — supply the reserves you'll need to draw on throughout the day.

Eat small, frequent meals

Where energy is the issue, it's better to eat small meals and snacks every few hours than three large meals a day. This approach can reduce your perception of fatigue because your brain, which has very few energy reserves of its own, needs a steady supply of nutrients. Some people begin feeling sluggish after just a few hours without food. But it doesn't take much to feed your brain. A piece of fruit or a few nuts is adequate.

Smaller is especially better at lunch. Researchers have observed that the circadian rhythms of people who eat a lot at lunch typically show a more pronounced afternoon slump. The reasons for this are unclear, but may reflect the increase in blood sugar after eating, which is followed by a slump in energy later.

Avoid crash diets

If you need to lose weight, do so gradually, without skimping on essential nutrients or starving yourself of the calories you need for energy. A sensible goal is to try to lose a half-pound to a pound per week. You can do this by cutting 250–500 calories a day from your diet, and exercising for 30 minutes on most days. Don't cut your food intake below 1,200 calories a day (for women) or 1,500 calories a day (for men), except under the supervision of a health professional. Eating too little can endanger your health, depriving you of needed nutrients. Poor nutrition and inadequate calorie intake can also cause fatigue.

Keep in mind that you need to eat regularly throughout the day, even when you're dieting. Your brain needs a steady supply of glucose from food. When the brain's glucose levels are low, some people feel hungry, fatigued, or both, which can then trigger a bout of overeating.

Use caffeine to advantage

As a stimulant, caffeine can increase or decrease your energy level, depending on when and how much of it you consume. Some studies have shown that drinking coffee before exercise increases endurance in both well-trained and weekend athletes, although other studies have found no such effect.

Caffeine does help increase alertness, so having a cup of coffee before going to a meeting or starting on a project can help sharpen your mind. But to get the energizing effects of caffeine, you have to use it judiciously. It can cause insomnia, especially when consumed in large amounts or after 2 p.m. (or noon if you're caffeine-sensitive). Some people are so sensitive to the effects of caffeine that having a single cup of coffee in the morning can interfere with their sleep at night. If you're such a person, you are best off avoiding caffeine entirely. Caffeine is mildly addictive, but moderate consumption hasn't been linked to disease.

Limit alcohol

One of the best hedges against the midafternoon slump is to avoid drinking alcohol at lunch. The sedative effect of alcohol is especially strong at midday, when you normally feel a bit lethargic anyway. Like a heavy lunch, an afternoon drink can exacerbate the lethargy.

Similarly, avoid the five o'clock cocktail if you want to have energy in the evening to pursue a hobby, spend time with your family, or finish that report for work the next day. If you're going to drink, do so in moderation at a time when you don't mind having your energy wind down. Because alcohol can have a stimulating effect several hours after you drink it, many experts advise against having a nightcap just before going to bed: It may help you to fall asleep, but two to three hours later the stimulating effect may awaken you and make it difficult to get enough deep, restorative sleep for the rest of the night.

Drink water

What's the only nutrient that has been shown to enhance performance for all but the most demanding endurance activities? It's not some pricey sports drink. It's water. Water is the main component of blood and is essential for carrying nutrients to the cells and taking away waste products. If your body is short of fluids, one of the first signs is a feeling of fatigue.

Sports drinks combine water with vitamins, minerals, and electrolytes — substances that help regulate body processes. But these extras won't give you extra energy for ordinary, everyday activities. You don't need them unless your workout is extremely strenuous or long, or if you sweat profusely and lose nutrients through perspiration.

How much water do you need? Although individual needs vary, the general advice usually provided is to drink eight glasses of water per day. But your requirements vary with the temperature, your level of physical activity, and what other foods and beverages you consume. Fruits and vegetables, for example, are loaded with water and can help meet your daily requirement. But caffeinated beverages such as colas, iced tea, and coffee can make you lose water and minerals through excess urination. Alcohol has a similar effect. So if you consume caffeine or alcohol, it's a good idea to drink extra water.

To maintain your energy level during a workout, drink two 8-ounce glasses of water before you start and two more after you finish. If you'll be exercising continuously for longer than 30 minutes, drink small amounts every 15–30 minutes.

Watch your glycemic load

The glycemic index is a measure of how quickly the sugar derived from a particular food is absorbed into your bloodstream. Doctors originally developed the index to help people with diabetes avoid foods that rapidly increase blood sugar, but some experts think the index is also useful in maximizing your natural energy levels.

In general, high-carbohydrate foods have the highest glycemic indexes (see Table 2). Proteins and fats have glycemic indexes that are close to zero. Foods with a high glycemic index can give a quick jolt of energy by increasing blood sugar levels. But the insulin pumped into the blood in response to this rise in blood sugar often leads to an equally sudden drop in blood sugar, leaving you hungry and, in many cases, feeling unfocused or foggy.

Eating foods with a low glycemic index — whose sugars are absorbed slowly — may help you avoid the lag in energy that typically occurs after eating quickly absorbed sugars or refined starches. Foods with a low glycemic index include whole grains, high-fiber vegetables, nuts, and healthy oils such as olive oil.

Power bars. It's impossible to walk into a drugstore or supermarket without seeing shelves lined with "power bars" that claim to boost your energy. The manufacturers of such products claim that they're superior to candy bars because they contain an "ideal ratio" of simple to complex carbohydrates, along with protein and fat. However, there's no proof that such an ideal ratio exists. A recent Ohio State University study compared the glycemic index of typical energy bars with other sources of carbohydrates. The power bars were no better than a candy bar at providing sustained energy.

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Last updated:	January 23, 2007