To the Editor.
—The study by Dr Schaefer and colleagues1 fills a major gap in understanding the effect of low-fat diets on lipid levels. During their study (approximately 3 months), two (6.9%) of the 29 subjects developed evidence of heart disease; one had a myocardial infarction. At this rate, approximately 25% of subjects would develop evidence of heart disease every year. In our clinical experience we found that low-fat diets using processed low-fat and nonfat foods deprived of essential fatty acids (EFAs) decrease high-density lipoprotein (HDL) levels and increase triglyceride levels. Some patients feel more tired and complain that they lack energy.We have been warning physicians that such low-fat diets increase the ratio of total cholesterol to HDL cholesterol, and deplete plasma and red blood cell EFA levels when used as maintenance diets (ie, without weight loss).2,3 Numerous studies show that low levels of polyunsaturated fatty acids