Mon, Apr-19-04, 20:11
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Butter Tastes Better
Posts: 5,201
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Plan: Atkins OWL / IF-23/1 /BFL
Stats: 100/100/100
BF:
Progress: 34%
Location: SF Bay Area
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Quote:
In a study partially funded by the AMA, a prodigious literature review on articles in English on the efficacy and safety of lowcarbohydrate diets was performed by use of Medline and other searches for those articles published between Jan. 1, 1966, and Feb. 15, 2003. All 2,609 potentially relevant articles were perused. All but 107 articles on 94 studies on 3,268 subjects receiving 0-901 g/day of carbohydrates for four to 365 days were excluded, but the reasons for exclusion of so many of the trials were obscure.
Only five studiesñwhich were non-randomized and had no control groups lasted more than 90 days. ì...These [lowcarbohydrate] diets have not been adequately evaluated for use longer than 90 days, or for individuals aged 53 years or older, or for use by participants with hyperlipidemia, hypertension, or diabetes.î
Conclusions in the abstract, verbatim, are that ìThere is insufficient evidence to make recommendations for or against the use of low-carbohydrate diets, particularly among participants older than age 50, for use longer than 90 days, or for diets of 20 g/d or less of carbohydrates. Among the published studies, participant weight loss while using low-carbohydrate diets was principally associated with decreased caloric intake and increased diet duration, but not with reduced carbohydrate content.î Of the two main ìlow-carbohydrateî groups into which the trials were divided, the 60 g/d groups mean intake of carbohydrate was 29 g/d, and total energy intake of all foods was 1,446 kcal/day. In the >60 g/d group the mean intake of carbohydrate was 236 g/d, and total energy intake of all foods was 1,913 kcal/day (their Table 3). In all 11 books on low-carbohydrate diets examined by this writer, any intake exceeding about 150-200 g/d of total carbohydrate would not be considered lowcarbohydrate.
In the true low-carbohydrate group the mean weight loss in trials was 17 kg, while in the higher-carbohydrate group it was 2 kg (their Table 5). The authors do not consider this significant and attribute the result to the lower total caloric intake. This view has been falsified in several studies. For example, controlled trials in hospitals have shown that a diet of just 1,000 kcal/day that is 90% carbohydrate led to weight gain, and intakes of 1,000 to 2,600 kcal/day with a very low carbohydrate content led to weight loss.
Thus the conclusions should have been that low-carbohydrate diets are both safe and effective. Only by intermingling trials of low to medium and high-carbohydrate diets could the authors reach the conclusions quoted above.
Arecent one-year diet trial supposedly designed to evaluate the Atkins diet examined 63 subjects, of whom the 33 assigned to the Atkins diet were given a copy of Atkinsís 2002 book and instructed to follow it, including no restriction on the amount of fat and protein. The 30 assigned to the low-fat diet ñ 60% carbohydrates, 25% fat, 15% protein by fuel values ñ were restricted to 1,200- 1,500 kcal/day for women and 1,500-1,800 kcal/day for men, definitely a slimming diet. Conclusions in the abstract, verbatim, are: ìThe low-carbohydrate diet produced a greater weight loss (absolute difference, approximately 4%) than did the conventional diet for the first six months, but the differences were not significant at one year...î All subjects met with a registered dietician four times. Since registered dieticians are indoctrinated by the American Dietetic Association to promote high-carbohydrate diets, this variable was not properly controlled, since the controls would have had reinforcement (placebo effect) and low-carbohydrate subjects would not (nocebo effect).
In addition, subjects were excluded if they were ill, had noninsulin dependent diabetes (NIDDM), were taking lipid-lowering medications or ones that affect body weight, or were pregnant or lactating. In other words, many subjects who would have benefited the most from the Atkins diet were excluded; this was the most serious fault in the trial design. Nevertheless, there was more weight loss among subjects on the Atkins diet, highly significant at 3 and 6 months, but claimed not to be significant at 12 months using all participants, including those who did not complete the study, but whose values were extrapolated to 12 months so as to show nonsignificance.
The absolute weight loss difference was actually 3% between groups, favoring the low-carbohydrate group, at 12 months, among those actually completing the study, and this was shown as significant in their Fig. 1B. Low-carbohydrate dieters had increased high-density lipoproteins (HDL) and decreased triglycerides (TG). Adherence was poor and attrition high in both
groups, but attrition was less in the low-carbohydrate group. More trials were recom-mended, and all the usual discredited shibboleths about low-carbohydrate diets were resurrected ñ kidney and liver damage, higher cholesterol intake ñ including the unfounded concerns about saturated fat consumption.
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http://www.aapsonline.org/jpands/vol9no1/kauffman.pdf
Last edited by Karen : Tue, Apr-20-04 at 10:35.
Reason: Removed double spacing
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