low-carb diets in perspective

EXPERTS ANALYZE THE HEALTH APPLICATIONS

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 found 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 nonprofit organization founded by former US Surgeon General C. Everett Koop, reported that low-carb diets are frequently misunderstood. For example, there is a widespread 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).

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.

Early in his career, Dr. Atkins emphasized the importance of extra fat intake in the diet as an indirect mechanism for weight loss. I find this notion to be of some concern, especially if people on the Atkins' Diet make excessive use of saturated fat. It is important to note that, over several years, Dr. Atkins did change his mind about the type of fat that he recommended in his diet. At one time, he did not distinguish between saturated fat and healthful types of fat, such as those found in vegetables and fish (especially omega-3 fatty acids). Toward the latter part of his life, Dr. Atkins recommended the use of essential fatty acids and certainly concentrated much attention on the use of omega-3s. Key members of Dr. Atkins' staff played a pivotal role in changing his thoughts about healthful types of fat.

Continuing Investigation
In January 2004, another media brouhaha developed when the "overemphasis of red meat" in the Atkins' Diet was criticized. A quick response from Atkins Nutritionals noted that Dr. Atkins had been recommending other sources of protein for several years prior to his death. In personal conversations with Dr. Atkins, he expressed to me his support of partial vegetable protein inclusion in the diet.

Dr. Atkins realized it wasn't practical for people to completely abstain from carbohydrates for life, and he recommended carbohydrate reintroduction as part of his dietary plan. We know from recently published research in the May 22, 2003 issue of The New England Journal of Medicine (NEJM) that in the early phases of the Atkins' Diet, accelerated weight loss does occur — and it's not just water weight. This was a meritorious finding with the Atkins' Diet.

Concluding with Caution
There has been a monotonous, unsubstantiated warning in the media that extra dietary fat intake in the Atkins' Diet could, perhaps, cause dieters problems with high blood cholesterol or other risk factors for heart disease. However, the research on the Atkins' Diet published last year in NEJM showed that blood cholesterol values were not negatively influenced by the increased fat intake in the diet to any major degree.

YouTube video:

GRAPH: Figure 1: As the nations weight rises, the occurrence of maturity onset (type 2) diabetes mellitus gallops. Notice the short period (10 years) in which this situation has emerged. This illustration supports Atkins' notion of "diabesity."

PHOTO (COLOR): Dr. Holt believes that the combination of a low-carb diet, proper supplementation and exercise can help you lose weight — and keep it off.

PHOTO (COLOR)

Resources:
Holt S, Combat Syndrome X, Y and Z..., Wellness Publishing, Newark, New Jersey, 2002

Holt S, Enhancing Low-Carb Diets, Wellness Publishing, Newark, New Jersey, 2004

Holt S, Wright JV, Nutritional Factors for Syndrome X, Wellness Publishing, Newark, New Jersey, 2004

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By Stephen Holt, MD

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