An energy solution: What you're eating for

You just got home from a long commute. The train was hot and you’re feeling a little low, a little slow. You won’t eat dinner for a few hours and you need energy to finish some chores in order to relax for the evening. But you’re disappointed to find that there are no more Gatorade drinks and no more energy bars. You can only find a half-finished jug of milk and some unsalted cashews.

Out of luck? Hardly.

We’re trained to compartmentalize our foods: Energy foods, Junk foods, Health foods, Fast foods, Slow foods. Partly, the corporatization of the food network is to blame, but not entirely. Compartmentalization is a handy way to make sense of the flood of dietary information we receive nearly constantly from online media, health columnists, nutritionists, doctors and advertisers. The idea of eating has become so overwhelming that sitting down to plan a meal can feel like charting a course through unknown seas. The labels we apply liberally to our foods serve as buoys clanking in the night.

But referring to Gatorade drinks and Cliff bars as Energy foods obscures things. Why? Because all foods are “energy foods.” Food is energy, plain and simple. Food is other things as well, but at its essence, it is energy. And just as not all food is the same, not all foods provide the same type of energy. So rather than rely on the corporatized food groups or the trendy foodie buzzwords, we need simple, practical ways to understand what we’re eating and how it affects us in the short term.

So, here are some energy basics for the casual eater. The calorie lies at the root of the matter. The calorie means everything—and at the same time, it means nothing—about food energy. A calorie (which is actually a kilocalorie, shortened so folks in the U.S. digested the term) is simply a measure of energy, similar to a joule or BTU. A food’s caloric value describes the amount of energy available to the body. So, if you were to think of your body as a furnace that could burn anything—wood, coal, petroleum, food grease—calories would be the most important aspect of your diet.

But the human body is not an ignorant furnace. For each person, there are energy sources (foods) that help it run optimally and others that make it run poorly. In other words, not all energy sources are the same, and since the human body is so sensitive, the calorie is nearly meaningless in terms of guiding our eating.

Fortunately, we’re already familiar with the fundamentals of food energy, though we may not always realize it. The key components of the human diet—carbohydrates, fat and protein—are also the energy sources powering the human body. Fats are the most energetic foods and carbohydrates and proteins are roughly the same, providing about half the energy of dietary fat. Of course, all three act very differently. Even within the carbohydrate family, sugars, starches and fibers (found in everything from fruits, to vegetables to meats), the body differently. Most importantly, knowing the caloric value is not enough to gauge a food’s energy impact. For example, you may find that a slice of wheat bread and a tablespoon of raisings provide the same amount of energy. Except the raisins pack a surprisingly quick energy punch whereas the bread is more slow-acting.

So, where does that leave you? There you are, looking for energy, staring at the milk and wishing for Gatorade. Comparing the two, Gatorade is super-concentrated with sugars, along with salts, potassium and other boosters. Going back to the furnace analogy, the sugars in Gatorade act like dried pine needles added to a fire. There is a burst of light, a pleasant smell and a warm feeling. With sugar, as with pine needles, the energy peaks quickly and disappears—the so-called sugar low. The so-called sports drink, on the other hand, stuffs you so full of fast, cheap energy that you’re bound to spike and crash your system (and risk long-term health complications). Milk, on the other hand, provides protein and fat (along with lactose, a more-complex carbohydrate), the type of energy that fills you up and keeps you steady. Proteins and fats are more like the sticks and logs of the food-as-fuel analogy. Choose a "whole food" and you won't be left half-fueled.

Thinking about food energy is not an easy solution to dietary conundrums. We don’t eat simply to garner energy. We also eat to feel content, to meet others, to share love and friendship, to socialize. But reimagining the daily diet in terms of energy balance makes it easier to gain confidence in your ability to make healthy and fulfilling food choices.