Do you think an Energy Bar will make you energetic, or that a Power Bar will build muscle? That's what their marketers want you to believe.

All foods give you calories (energy), but if you don't move and burn the calories you eat, you will store them as fat. How many Energy Bars do you think they'd sell if they called them Calorie Bars?

If you're running a marathon, cycling 100 miles or hiking all day, energy bars are a convenient way to get the calories you need. But if you're sitting at a desk feeling sleepy, the last thing you need is an "Energy Bar"! That blast of refined carbohydrates and sugar will raise your blood sugar, causing you to pump out insulin, store the calories as fat and feel tired and hungry again in half an hour.

Protein does not build muscle. YOU have to work against resistance to build muscle. When you build muscle, you use protein from the food you eat, but any extra protein you eat is stored as fat. A reasonably varied diet provides plenty of protein. If you are doing heavy weight training, you can eat a little more tuna, milk, beans or any other food source of protein. Protein bars, shakes and supplements are not better than food.

Energy bars are made of sugar, refined carbohydrates and fats, fortified with small amounts of vitamins and minerals the nutritional equivalent of a cookie and about 1/6 of a multivitamin pill. Protein bars add milk or soy powder. They are not more nutritious than a bowl of cereal, and they cost a lot more.

Energy & Power Bars - $8.00-$20.00/pound $1-4/serving

Breakfast Bars - $6.00/pound $.75-$1/serving

Oatmeal Cookies $3.00/pound $.30/serving

Cheerios - $2.50/pound $.20/serving

Vitamin pill $.16/day

Whole grains - $0.89/pound $.05/serving

No bars provide "complete nutrition," and should not be used as substitutes for meals. They will not make you more muscular, thinner or more energetic. Eat a varied diet with plenty of fruits, vegetables, whole grains, beans and other seeds, and treat these bars as cookies or candy bars for occasional treats or convenient snacks during endurance sports.

Gabe Mirkin, M.D.

Dr. Gabe Mirkin has been a radio talk show host for 25 years and practicing physician for more than 40 years; he is board certified in Sports Medicine and three other specialties.

Dr. Mirkin's daily features on fitness have been heard on CBS Radio News stations since the 1970's. He has written 16 books including The Sportsmedicine Book, the best-selling book on the subject that has been translated into many languages. His latest book is The Healthy Heart Miracle, published by HarperCollins.

Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. A Boston native, Dr. Mirkin did his residency at the Massachusetts General Hospital. He has served as a Teaching Fellow at Johns Hopkins Medical School, Assistant Professor at the University of Maryland, and Associate Clinical Professor in Pediatrics at the Georgetown University School of Medicine. He has run more than forty marathons and is now a serious tandem bicycle rider with his wife, nutritionist Diana Mirkin.