As a registered dietitian, and someone who specializes in sports nutrition, I was appalled when the low carbohydrate fad came into popularity. However, I also predicted that in a couple of years people would become better educated and ready to really pay attention to how to eat for health. Yes, people lost weight, but mostly because they eliminated many of the high fat, high calorie snack foods and meals they were previously eating. Unfortunately, the foods that promote health were also eliminated as all carbohydrates came under attack. Gone were the chips but also gone were the fruits and vegetables so high in health-promoting nutrients. Even worst of all was the increase in animal fats that are known to promote disease and inflammation. Lets first address why the low carb diets bothered me. Carbohydrates are one of the three major nutrients in our diet, known as macronutrients. Protein and fat are the other two. These three nutrients supply most of our calories, with alcohol being the fourth. All foods break down into glucose, which is our primary fuel and the only fuel for the brain. No matter what, the brain needs glucose to survive. Even some of fat breaks down into glucose. During the low carb diets, people were instructed to avoid all obvious carbohydrate foods, and in some diets were even encouraged to check their levels of ketones in their urine. Ketones are a byproduct of impartial fat metabolism for people who are not getting enough carbohydrate in their diets or, for medical reasons, are not utilizing the carbohydrates they are eating. However, carbohydrates are the primary fuel for breaking down body fat during exercise. So, here we have people who want to lose weight trying to also exercise, but because they are not eating the primary fuel for that exercise, their exercise intensity suffers. As a consequence, they burn fewer calories during exercise and cannot burn as much body fat. Not only does science support this, but I would see this happen with my own clients. I also used myself to experiment on. One of my clients challenged me to try the Atkins diet. Never mind the effect of cutting out all my fiber in my diet (constipation), but by the third day I felt like I had lead feet when I tried to do my usual workout! I had no fuel in my body at all. By day #5, I felt I was doing my system more harm than good and went back to my fruits, vegetables and whole grains. Ahhh. Also, I had not consciously realized just how high my diet was in whole grains, fruits and vegetables, and how low it was in animal products, particularly animal fats. This brings up the other problem I had with these diets. More research than I can mention has shown the advantages of a diet high in fruits, vegetables and whole grains. Because of the phytochemicals in these foods, it has been shown that people who eat high amounts of these foods not only weigh less but their health benefits from the high intake of antioxidants and vitamins. Studies looking at cancer and heart disease continually conclude that high intakes of these foods benefit health. My own experience with clients has also shown this. Most people already eat too few servings of fruits and vegetables. Once they increase them, however, they find themselves filling up on fewer total calories. Not only do they start to feel better but they start to lose weight! Starches still have a bad rap, but once people realize the difference between one starch and another, we may actually see more people eating diets consisting of whole, unrefined foods. So, I guess the benefit of the high protein, low carb diets may be the new awareness that people have in the value of eating unprocessed, whole foods, and that all foods really DO fit into our diet. |
