One of the most persistent ideas in nutrition is “a calorie is a calorie” and that it doesn’t matter if a particular calorie comes from protein, carbohydrate, fat or alcohol. Consume too many, and you’ll gain weight. Too few, you’ll lose.
If the problem is excess bodyweight, counting calories appears to be a clear and simple strategy for losing some extra pounds – fewer calories in (eat less) and more going out (exercise more). However, this scenario is seriously incomplete because one calorie can differ dramatically from another in its ability to provide you with energy or add fatty tissue to your body. Consuming carbohydrates boosts production of insulin, and the body’s level of free-circulating insulin determines if calories are stored as fat or not. As science writer Gary Taubes explains in his book Why We Get Fat, insulin also orchestrates the storage and use of fat and protein, making sure that muscle cells get enough protein for necessary rebuilding and repair and that you store enough fat and protein to function effectively between meals.
Simple math also gave us the decades-long low-fat dietary experiment of the late 20TH century. Since a gram of fat contains nine calories and a gram of carbohydrate only four, the best way to lose weight seemed to be cutting out calorie-dense fats. In fact, the low-fat strategy backfired, actually worsening the rates of obesity and diabetes in North America.
As Taubes points out in his book, that strategy went against centuries of knowledge that eliminating or reducing intake of starchy carbohydrates and sweets promotes weight loss. For a detailed understanding of why this works and why the “calories in/calories” out strategy doesn’t, I recommend reading Why We Get Fat.
If you’re concerned about your weight, I suggest avoiding processed, refined manufactured foods that rank high on the glycemic index, meaning their carbohydrate content is quickly digested, raising blood sugar levels and stimulating insulin release. They’re the foods that are most likely to lead to weight gain.
For good health overall, I recommend an anti-inflammatory diet, with its emphasis on fresh fruits and vegetables, healthy fats, whole grains, fish and seafood and some cheese, yogurt, eggs, and occasional meat. Healthy sweets such as plain dark chocolate are included as long as you consume them sparingly. While it isn’t designed as a weight loss diet, many people find they lose weight on it if they don’t overeat and get regular physical activity.
Andrew Weil, M.D.
Gary Taubes, “Why We Get Fat And What To Do About It.” Knopf, 2011