The Problem with Energy Bars and Drinks

Recently I've noticed friends and co-workers snacking on energy bars (Clif Bars, Odwalla Bars, etc.) and other energy foods as well as drinking sports drinks like Gatorade and Powerade during the day. While arguably better than candy bars and soda (though not by much in some cases) there's a hidden danger to this kind of snacking. Even when they're watching the saturated fat, hydrogenated oils and cheap sweeteners (e.g., corn syrup), they may not realize that these foods and drinks are specifically designed to be "calorie dense" -- precisely what you don't want when you're sitting at a desk most of the day. Your typical energy bar has somewhere around 250 calories. Compare that to your average "granola" bar and you'll see that you're taking in roughly twice the calories.

Caloric density is the measure of calories per gram of a food. The purpose of energy bars and drinks, as their name should imply, is to supply extra energy before and during exercise. "Recovery" foods are designed to supply extra protein and carbs immediately after exercise. Neither are meant to be consumed as snacks, though you can be sure manufacturers won't go out of their way to prevent people from eating more than they should.

In simple terms, athletes should eat calorie dense foods just before and during exercise (during exercise only if the activity is expected to take more than 2 hours -- otherwise it's counter-productive to eat since it won't be metabolized quickly enough to help). After exercise you should immediately consume recovery foods (high protein and carbs) before returning to low caloric density foods.

What, you might ask, are low caloric density foods? Generally speaking, foods from the world of plants (fruits, vegetables, grains, etc.) have low caloric densities and foods from the animal world have high caloric densities. For instance, an apple has a caloric density of 0.59 (calories per gram). A carrot -- 0.44. Grains are often even lower in caloric density. Brown rice, for example, has a caloric density of just 1.2 calories per gram. Contrast this with pork chops (2.28) or rib roast (3.31) and you get the picture.

But there's another very important phenomenon to note. Caloric density rises nearly exponentially when foods become heavily processed. Take corn, for example. Fresh corn has a caloric density under 1 calorie per gram, but processed corn, in the form of corn bread rises above 4 and corn chips weigh in at a whopping 5.5.

And finally, looking at the caloric density of an energy bar reveals why they're problematic as snacks. Most bars, by my calculations, have a caloric density of 3.5 or higher. Compare this again to fruits, vegetables and whole grains and you quickly see why snacking on energy dense foods is not your best approach.

An important related topic I'll address is a future post is the glycemic index of foods. The glycemic index (or GI) ranks carbohydrates according to their affect on blood glucose levels. Foods lower on the GI cause a less pronounced and more gradual effect on blood sugar levels, while higher GI foods cause rapid spikes. As with calorie dense foods, there are times when high GI foods are called for, and I'll discuss that soon!