In The News: "Lo-Carbs"

Some Observations About “Lo-Carbs”

            The Atkins Diet, the South Beach Diet, and other versions of diets containing a very low level of carbohydrates, so-called lo-carb diets, have been around for many years but have suddenly become remarkably popular.  They represent a dramatic departure from long accepted nutritional ideas, and doctors and nutritionists have worried that the much higher percentage of fat in these diets poses a real threat of high blood cholesterol and arteriosclerosis (hardening of the arteries) to those people on them.

            The traditional theory of diets is that excess calories are all the same in producing body fat whether derived from fat, protein, or carbohydrates, and we know for certain that people today average about 350 total calories more per day than the previous generation and have far less physical activity. The only way to reduce extra body fat according to the traditional theory is to reduce overall calorie intake below the total needed for basic metabolic requirements plus physical activities so the body starts to use up its own stored fat for the its fuel needs.

            The lo-carb supporters believe something very different.  They doubt that the fundamental problem in obesity is the total number of calories from all sources that one takes in. Lo-carb theorists believe that the most important issue is that dietary carbohydrates flooding into the bloodstream after a meal provoke sudden changes in blood levels of insulin. This in turn, they say, creates a ravenous appetite for even more carbohydrates which exceed body fuel requirements so they add to body fat. They believe that one way to improve the situation is to eat only low glycemic index (GI) carbohydrates, i.e., carbohydrates that are digested relatively slowly and thus provoke less violent changes in insulin levels. 

            It has turned out to be surprisingly difficult to prove exactly how big a role the relation between dietary carbohydrates and insulin plays in the current epidemic of obesity, but ongoing U.S. government comparisons of various diets have so far suggested that the popular versions of lo-carb diets are unlikely to significantly drive up blood cholesterol.

     In an effort to find a path through the current confusion, we have decided to take the following positions on lo-carb diets pending further developments:

• ·        They appear to be useful in helping some people lose weight.

• ·        They do not appear to be harmful for most people so long as they are monitored.

• ·        It seems reasonable to limit total daily calories, at least somewhat.

• ·        We suspect that a substantial part of the reason that people lose weight on lo-carb diets is that the few remaining food choices soon becomes so boring that people actually eat fewer total calories than they previously did.

• ·        We do not think it is likely the average person will maintain a low-carb diet for a lifetime.  People often quickly regain the weight they lost when they return to ordinary levels of carbohydrates unless they learn to change prior eating habits when transitioning off of lo-carb diets.

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