Low-carb diets in perspective

Better Nutrition, May, 2004 by Stephen Holt

Almost every dieter in the United States has fallen in love with the idea of low-carbohydrate diets for weight control. Such diets include the Atkins' Diet, the Zone Diet, the Carbohydrate Addict's Diet, the South Beach Diet and the Sugar Busters Diet--each of which recommends reducing carbohydrate intake as a primary way for losing weight.

One of their principal attractions is that significant weight loss does occur relatively quickly, often within a month. That said, there are two specific issues associated with low-carbohydrate diets.

First and foremost, they do not result in long-term weight control. Second, they require nutritional and lifestyle "additions" to make them healthier.

The Sugar Story

My personal clinical experiences confirm this. I have witnessed failures from low-carb diets after 6 months to 1 year; in fact, a yo-yo effect may be much more common than many people may realize.

The point of maximum weight regain with the Atkins' Diet, for instance, occurs most often when people reintroduce carbohydrates into their diets.

Even Dr. Atkins himself recognized this limitation with carbohydrate reintroduction, especially when dieters started eating simple sugars again.

In fact, a key point is that simple sugars--and not necessarily all carbohydrates (for example, complex carbohydrates)--are the real cause of weight gain in the general population. Furthermore, the reason why low-carbohydrate diets may not work in the long-term is because the person with the weight problem often has resistance to the hormone insulin.

Contrary to popular belief, insulin resistance is not overcome by the low-carbohydrate diet itself, but insulin resistance can be partially reversed by weight loss.

The Importance of Insulin Resistance

Insulin is responsible for controlling blood glucose, but the hormone has many other functions in the body. When the body resists insulin, insulin production increases, and the body receives signals to store more fat--and that's why overcoming insulin resistance is a very important part of weight control.

But that's not the only health implication. Insulin also signals the liver to make cholesterol, so blood cholesterol rises. Furthermore, insulin gives a strong message to the body to raise blood pressure.

Dietary supplements that are designed to overcome insulin resistance can be quite valuable in making a low-carb diet more effective and healthier for many people. Then, too, there are many low-carb foods that offer "functional food components," including special types of dietary fiber, starch blockers and antioxidants, which together can complement carbohydrate restriction.

A new consensus may be emerging that the restriction of refined carbohydrates, along with calorie control, is a good foundation for weight management. Added to this approach is balanced protein intake with more emphasis on vegetable protein.

Fat has also attracted special attention as the benefits of polyunsaturated or super-polyunsaturated fats become clear. These healthy fats include omega-3 fatty acids round in fish oil or in a precursor form in some plants (e.g., flax and soybeans).

All low-carbohydrate diets require modification if they are to be successful in the achievement of sustained weight control or weight loss. I believe that the control of insulin resistance, which is the basis of Syndrome X, is obligatory for sustained weight control and health in many people. This is the rationale behind my proposal that low carbohydrate diets or "lifestyles" require additions or "facilitators" to provide more than just the short-term weight control or weight loss most often experienced with these regimens. All diets work better when they are structured; and the use of lifestyle strategies and health-giving dietary supplements can help to structure them.

Scientific Argument

A survey released in December 2003 by Shape Up America!, a non-profit organization founded by former US Surgeon General C. Everett Koop, reported that low-carb diets are frequently misunderstood. For example, there is a wide spread misconception among low-carb dieters that calories do not count, which, of course, is not true. In addition, Shape Up America! drew attention to the negative health consequences that occurred in three doctors who followed a strict low-carb diet. While each doctor lost weight, one was admitted to the hospital with severe constipation and one experienced a 24 percent increase in levels of low-density lipoprotein (LDL), or "bad" cholesterol. In fairness, however, these findings cannot be taken to be representative of the average outcome of a low-carb diet.

Even though low-carb diets continue to be criticized, the value of restricting simple sugars has become increasingly clear with the mounting pandemic of Syndrome X, prediabetes, type 2 diabetes mellitus and a frightening association of obesity with diabetes that Dr. Atkins termed "diabesity" (Figure 1).

[FIGURE 1 OMITTED]

Finding Healthful Fats

Even though science has questioned some of the theories behind the Atkins' Diet, recent studies have implied that the Atkins' Diet may be quite effective for weight loss, at least in the short term.