There’s one thing you can count on when it comes to diet advice: it’s always changing. For years, I’ve promoted the benefits of eating whole foods sourced as close to nature as possible—not only from a healthy weight standpoint, but also for overall health. In the past, calorie counting was the primary message of conventional weight-loss strategies in our culture, but it finally seems to be catching on that it’s not just about calories—even in the diet industry. In fact, not all calories are created equally, so people are turning more to caloric quality, not quantity.
The trend now is that health- and weight-conscious people are less concerned about caloric restrictions and more concerned about nourishment. In fact, some market research among health- and weight-conscious people found that their top preferences were not for low-calorie foods, but for high-quality, fresh, nutritious and organic ingredients in their food.
Don’t get me wrong. Calories do count, but they’re not the only measuring stick. Eating nutrient-dense foods is weighing in much more heavily these days.
But what about those calories? We know that we get calories from the foods we eat and what we drink, but what happens after that? When we eat, the chemical processes that make up our metabolism break down the food and turn it into energy for us to use. Ah…there’s the key: metabolism. It’s how calories are metabolized that makes the difference.
The idea that “a calorie is a calorie” has been the basis of conventional weight loss strategies for years, but people are realizing that not all calories are alike. There may not seem to be a difference between 500 calories of Twinkies (for the Twinkie diet guy) or 500 calories of fresh veggies and fruits—until the calories are metabolized. The calories you eat are absorbed at varying rates and have differing amounts of protein, fats, carbs, fiber and other nutrients which translate into various complex metabolic signals controlling your weight.
For example, sugar from processed carbs enters your blood quickly, while sugar from legumes enters your blood slowly. Sugar going into your bloodstream all at once leaves the calories you’re not using to be stored as fat. If, however, sugar from another food is absorbed over time, then your body has more time to burn those calories and not store them as fat. In short, high-carb diets made up of rapidly absorbed sugars increase blood sugar and insulin levels, cause weight gain and increase cholesterol and triglycerides. That can lead to a fatty liver, which can cause even more weight gain.
Leading nutrition researchers, including Walter Willett, M.D. and his group from the Harvard School of Public Health, designed a study on calories and weight loss. Here’s what they found: one group was fed a low-fat diet—1,500 calories for women and 1,800 calories for men—while another group was fed a low-carb diet of the exact number of calories. A third group also consumed a low-carb diet, but ate 300 more calories a day than the other groups—1,800 for women and 2,100 for men.
The results? Over 12 weeks, the low-carb group eating the same number of calories as the low-fat group lost more weight—an average of 23 pounds compared to 17 pounds for the low-fat group. (That’s six more pounds of weight loss over 12 weeks.) The difference? The low-carb diet was mostly whole, unprocessed foods like lean animal protein, veggies, whole grains and beans. The low-fat group included more refined carbs. Both groups ate the same number of calories, but those who ate the whole, unprocessed foods had greater weight loss.
Here’s the kicker, though. The group eating 300 more calories a day with the low-carb diet lost more weight than those eating the low-fat diet—even though the extra 25,000 more calories they ate should have appeared as seven pounds of increased weight. They lost an average of 20 pounds more than the low-fat group who ate 25,000 fewer calories during those 12 weeks.
Calorie quality is more important than calorie quantity because the type of calories you eat has an impact on how your metabolism functions. Your diet—in the quality of calories you consume—impacts what your genes tell your metabolism to do.
You can see why calorie counting has been countered.