The philosophy behind so-called "low carb" diets such as the Atkins Diet is that obesity is primarily the result consuming too many carbohydrates, and that the traditional medical focus on lowering fat intake is partly to blame for obesity in the United States. The theory underlying the Atkins Diet philosophy is that carbohydrate consumption stimulates elevated insulin levels in accordance with their relative position on the "Glycemic Index" familiar to diabetics. According to Atkins, the recent rise in obesity in the United States is partly the result of governmental advice to minimize high-fat foods in favor of carbohydrates (Atkins, 1999).
The mechanism employed by the Atkins program relies on stimulating a natural condition known as ketosis by artificially provoking an evolutionary adaptive response that was originally designed to protect us from starvation in times of scarcity. Atkins accomplishes this by dramatically restricting carbohydrates, especially in its initial stages, while increasing the intake of fats and proteins without restriction (Atkins, 1999).
Initial weight loss results are sometimes dramatic, but under analysis, the reason for this does not comport closely with Atkins claims or philosophy.
Furthermore, most medical authorities and nutritional experts maintain that whether or not Atkins results in successful weight loss, there are potentially serious medical consequences of long-term consumption of high-fat, high-protein diets.
The Atkins literature suggests that numerous studies corroborate the safety and efficacy of the Atkins program, but further analysis reveals that none of the supportive literature was subjected to impartial (let alone scientifically rigorous) peer review.
Rather, much of it was funded by Atkins proponents with a financial stake in substantiating its claims. Other studies promoted as validating Atkins were found to be scientifically invalid by virtue of their failure to include information that nearly half the subjects of the studies were unable to complete the study because they could not maintain the program, even for the short-term (Blackburn, 2002).
Ultimately, whether or not Atkins is a successful weight loss program is probably something of a moot point in that even in the most favorable light, it fails to achieve long-term positive results for reasons much simpler than the variables and peer review procedures of medical studies. No diet can be considered "effective" if it produces results that are incapable of being maintained for the long-term. Wholly apart from the reasons Atkins seems to work initially and the medical health and safety concerns at issue in major studies, Atkins has never been subjected to long- term studies that establish success rates in relation to those of "conventional" weight loss diets. Anecdotal evidence suggests quite strongly that Atkins dieters are no more likely to maintain any weight lost on the program than are dieters of any other weight reduction programs (Blackburn, 2002).
The Atkins Diet Theory:
The human body normally stores energy in the form of glycogen, which is stored within the muscle cells as well as in the liver. Glycogen is produced by metabolic processes which convert calories consumed in excess of immediate energy needs into a storable form of usable energy. Energy is also stored as body fat when caloric consumption surpasses a threshold, based on individual differences in metabolic rate and related genetic factors.
By severely restricting all carbohydrates, Atkins dupes the body into reacting as though it is being starved, because to a large degree, the metabolic triggers for emergency utilization of stored fat reserves depend on carbohydrate levels in the bloodstream. Once the process of ketosis is achieved by sufficiently depleted blood glucose levels, the body begins burning nutrients for immediate energy rather than storing excess calories (Westman, 2002).
Ketosis allows one to consume fats and proteins in much greater quantities than normally possible without dramatic weight gain, provided the condition of ketosis is maintained. According to the Atkins literature, the secondary effect of the Atkins program is the metabolic breakdown of body fat into ketones excreted in the urine. Some Atkins dieters do experience tremendous weight loss, and many report that Atkins is easier for them to maintain than conventional diets (Hellmich, 2000).
Refutation of Atkins Diet Theory:
The first refutation of Atkins Diet theory relates to the origin of at least some of the weight lost in the initial stages. Under normal circumstances, carbohydrate consumption is associated with a certain degree of water retention in much the same manner as salt consumption is associated with water retention. When carbohydrates are artificially restricted and glycogen stores depleted to minimal levels, significant water is excreted in addition to any stored fat, and reports of dramatic weight loss on Atkins fail to acknowledge or take this element into account (Bravada, 2003).
The second refutation of Atkins Diet theory is that in terms of weight loss, it is merely a low calorie diet in disguise. High-fat foods are much more satisfying to the appetite than are most carbohydrate counterparts. Atkins dieters are allowed many foods that have always been restricted on the traditional diets with which they have typically) struggled on and off for years. When these dieters are allowed to consume high-fat foods while restricting carbohydrates, they simply consume fewer calories because of the satiation factor long known to be associated with high-fat foods. In many respects, Atkins is simply an easier way for dieters to lower their caloric intake, albeit without intending to or even realizing it, necessarily (Hellmich, 2000).
The third refutation of Atkins Diet theory is that it fails to distinguish amongst simple carbohydrates and complex carbohydrates, treating them all as culprits in obesity. Carbohydrates are composed of molecules ranging tremendously in their complexity and numbers of molecular bonds. The simplest carbohydrates are refined sugars and bleached flours. Simple carbohydrates require comparatively little energy for metabolic processing and convert very readily into their component sugars, which Atkins theory correctly implicates in stimulating pancreatic production of insulin.
Insulin spikes are always followed by corresponding low blood sugar, which triggers fatigue and also stimulates the appetite. Therefore, to the degree that Atkins Diet theory advocates lowering consumption of simple carbohydrates, it comports with established nutritional science (Westman, 2002).
However, Atkins theory also restricts complex carbohydrates, which does not comport with established nutritional concepts. Complex carbohydrates require significantly more energy to metabolize, by virtue of the relative complexity of their molecular structure and the number of chemical bonds within each molecule. As a result, complex carbohydrates are more readily stored in the form of glycogen and much less readily released into the blood to provoke an insulin response, or stored as body fat. Because complex carbohydrates contain fewer simple sugars, they are not associated with the same degree of water retention as simple carbohydrates, either.
Calories greatly in excess of immediate energy requirements are eventually stored as body fat, regardless of their original source. Atkins theory is correct when it highlights the deleterious and inefficacious effects of dieting by merely replacing fats with indiscriminant amounts of simple carbohydrates, such as low-fat desserts. What Atkins theory fails to address in its vitriol against "carbohydrates" is that traditional nutritional concepts do not advocate excessive consumption of simple carbohydrates.
The Atkins literature completely ignores the value of diets that restrict simple carbohydrates in combination with reliance on complex carbohydrates as part of a balanced, low-fat, low-simple carbohydrate diet of moderation (Blackburn, 2002).
The fourth refutation of Atkins Diet theory lies in the tenuous nature of maintaining ketosis over the long-term. Another failure of the literature purporting validate the program is that it ignores the difficulty often inherent in maintaining the requisite low level of carbohydrate consumption in the long-term. Forty percent of subjects in one pivotal study proved unable to maintain the program even for the six months of the study. Typically, they reported symptoms such as headaches, lethargy, fatigue, depression, halitosis and extreme difficulty concentrating on intellectual tasks. This hardly surprised nutritionists, since the only source of energy for the human brain is glucose, normally supplied in sufficient quantities by a balanced diet that includes carbohydrates (Bravata, 2003).
When weight loss (and weight loss maintenance) is predicated upon maintaining a state of ketosis artificially, it is profoundly susceptible to deviations. In many respects, diets relying on ketosis are profoundly more delicate to upset by any lapse than are balanced diets merely intended to reduce caloric consumption.
Whereas a conventional dieter who goes off his diet can simply resume his nutritional regimen without complication, a dieter dependant on ketosis encounters immediate problems with virtually any deviation. In a state of ketosis, the dieter may eat high fat foods because the absence of carbohydrates allows him to burn fat as a primary source of energy. As soon as he exceeds his allotment of carbohydrates, ketosis is compromised and the body immediately begins storing fats as it does under normal non-ketosis) metabolism. Consequently, the dieter experiences an immediate increase in weight almost immediately after any temporary deviation from the program. The results of exceeding the consumption of carbohydrates allowed under Atkins is compounded by the fact that much of…