Diet Wars: From Atkins to the Zone. Who Is Right?

VOL. IV NO. II MARCH/APRIL 2002 130 Last week I saw a patient who told me that he had lost 70 pounds on the Atkins diet. When I asked him why he had chosen that particular diet, he replied with irrefutable logic, “Because I like eating meat. ” He admitted that he had subsequently regained at least half the weight, but his story is certainly not unusual. Most physicians do not do a very good job when giving patients dietary advice, and in fact, numerous surveys have shown that we usually just avoid the issue.1 There are several reasons for this: for one thing, most of us know little about nutrition, which in most medical schools gets little attention. For another, we do not place much confidence in our ability to persuade people to change their eating habits. We are all too aware that the public is bombarded with advice and advertisements about food and diet. We are also aware of the epidemic of obesity in the United States, but we feel powerless to do anything about it. When it comes to giving dietary and lifestyle advice, most of what we tell our patients is negative, so when our patients hear the message of Dr. Atkins— that you can quite literally have your cake and eat it, too—it is naturally very seductive. If you read the books or access the web site, it sounds, to most of us, too good to be true, and as we shall see, it almost certainly is. The claims that are made are that a low-carbohydrate/high-fat diet will make you lose weight, eat less, feel better, and enjoy better health. The rationale for the diet is that eating carbohydrates leads to insulin release, which makes us hungry, and also leads to an increase of triglycerides. This view is a key component of several other popular diets (the Zone Diet, Sugar Busters’ Diet, Protein Power Diet, etc.), all of which assume that carbohydrate is the culprit. But at the other extreme of the diet popularists is Dean Ornish, who takes the opposite view (somewhat closer to the traditional view of organizations such as the American Heart Association) that fat is the villain. So what are we to do? The politically correct diet, recommended by bodies such as the American Heart Association, is that we should eat more carbohydrate and less fat, but who among us has had a patient who has lost 70 pounds as a result of our advice? Part of the problem in interpreting the effects of an Atkinstype diet is that there is very little published about it in the medical literature. There are, however, problems with it. First and foremost is what we know about the adverse long-term effects of high-fat diets. The lipid hypothesis, which is now undisputed by the vast majority of physicians and scientists, was originally based on blood lipid levels rather than on actual food intake, and the Atkins claim is that the highfat/high-protein/low-carbohydrate diet does not raise blood lipids. Now, however, we have several studies that relate actual food intake to disease. A survey of coronary heart disease mortality in 40 countries found that, with two notable exceptions (France and Finland), the different death rates in different countries could be explained by differences in the intake of cholesterol and saturated fats.2 Furthermore, the progression of coronary artery disease has also been correlated with the intake of saturated fat.3