To the Editor: The Atkins diet was first introduced to American markets during the 1960s. It was ridiculed for more than 30 years, not only as a fad diet but as dangerous nonsense as well. Some nonrandomized studies were reported after the turn of the century1 and many before that.2 All those short term studies had shown that the Atkins diet and similar low-carbohydrate diets can initially bring better results than conventional low-calorie, low-fat dietary regimens. In addition to its probable favourable effect on body weight, the popularity of the Atkins diet stemmed from the freedom it offers to consume as much protein and fat (for example meat, fish, chicken, eggs and cheese) as the dieter wishes, while carbohydrate intake must be restricted to no more than 20g a day, initially.
However, numerous studies have shown that low carbohydrate diets are unlikely to produce significant long-term weight loss and may lead to serious health problems. The caution of leading medical and nutrition organizations worldwide against all low carbohydrate diets stems from the fact that these diets greatly increase fat and protein consumption, which could lead to many serious ill effects, and greatly restrict consumption of essential nutrients: minerals, trace elements and vitamins, and fiber—all of which promote improved health and help prevent many diseases.
To start with, low-carbohydrate diets force the body to use fats as the main energy source, leading to ketosis. The brain, thereby devoid of its main energy source, glucose, is forced to make use of the metabolic breakdown products of fats and ketone bodies, leading to common side effects: nausea, dizziness, constipation, headache, fatigue, and smelly breath. In addition, ketosis leads to metabolic dehydration whereby the body consumes its own water stored within the body’s broken down proteins, leading to initial additional weight loss probably over and above that caused by a conventional low-calorie, low-fat diet.3
However, being unrealistic and unconventional, the low-carbohydrate diet is neither palatable nor enjoyable enough to be followed for a long time, resulting ultimately in an insignificant difference in weight loss compared with low-calorie, low-fat diets—hence the inability to conclude with confidence whether the weight loss is actually due to the low-carbohydrate diet. This was clearly highlighted by the two longest (12 months) randomized investigations. 4,5 Moreover, weight loss due to low-carbohydrate dietary regimens is unsustainable when carbohydrates would and should be reintroduced as a logical return to normal dietary habits asclearly manifested by the report of the United States National Weight Control Registry,6 which analyzed diets of 2681 individuals who followed a low-carbohydrate dietary regimen. The report indicated that those who maintained at least 30 lb/~13 kg weight loss after a year or more and who still follow a low-carbohydrate diet (<24% energy from carbohydrate) constituted <1% of the sample studied.
The American Heart Association was one of the pioneers in issuing a warning against high-protein, high-fat, low-carbohydrate diets as a means of losing weight.7 This warning supAnn ported an earlier one:8 “the very high fats of Atkins diet: 60%–68%, around 26% of which are saturates, through shifting the metabolic pathway for energy production, deliver a strong boost to free radical production, thereby increasing oxidative stress on different organs”. For example, the increased oxidative stress on the heart muscle9 coupled with the low potassium in cardiac tissues resulting from the loss of minerals due to metabolic dehydration3,8 could have serious, even fatal, consequences. Moreover, the increased oxidative stress coupled with reduced fiber intake of a low-carbohydrate diet increases the risk of cancer of the lungs and gastrointestinal tract.8
The Atkins diet and similar low-carbohydrate diets could have other deleterious effects as well. The high protein of a low-carbohydrate diet could lead to hyperuricemia (leading to joint pain and gout) and hypercalcuria (leading to kidney stones, hypocalcemia, and osteoporosis). Moreover, a Harvard study10 showed that high protein diets may cause permanent loss of kidney function in any one with reduced kidney function, a not uncommon probability since as many as one in four Americans, for example, may already have kidney problems.11
The American Diabetes Association also cautioned against use of low-carbohydrate diets. Studies in healthy subjects and those at risk of type 2 diabetes support the importance of including foods containing carbohydrates from whole grain, fruits, vegetables and low-fat milk in the diet. The same view has been adopted by the American College of Preventive Medicine and the American Dietetic Association.12
In conclusion, it is imperative to stress the importance of losing weight in a healthy manner that neither exerts added stress on the body’s vital organs nor leads to weight snap back when carbohydrates are reintroduced in due course. In addition, it is essential to stress the point that “The greatest health benefits are derived from diets low in saturated fats and high in complex carbohydrates and fiber that increase insulin sensitivity and reduce coronary heart disease risk.8
References
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