Effect of 6-month adherence to a very low carbohydrate diet program

Purpose To determine the effect of a 6-month very low carbohydrate diet program on body weight and other metabolic parameters. Subjects and methods Fifty-one overweight or obese healthy volunteers who wanted to lose weight were placed on a very low carbohydrate diet (<25 g/d), with no limit on caloric intake. They also received nutritional supplementation and recommendations about exercise, and attended group meetings at a research clinic. The outcomes were body weight, body mass index, percentage of body fat (estimated by skinfold thickness), serum chemistry and lipid values, 24-hour urine measurements, and subjective adverse effects. Results Forty-one (80%) of the 51 subjects attended visits through 6 months. In these subjects, the mean (± SD) body weight decreased 10.3% ± 5.9% (P<0.001) from baseline to 6 months (body weight reduction of 9.0 ± 5.3 kg and body mass index reduction of 3.2 ± 1.9 kg/m2). The mean percentage of body weight that was fat decreased 2.9% ± 3.2% from baseline to 6 months (P<0.001). The mean serum bicarbonate level decreased 2 ± 2.4 mmol/L (P<0.001) and blood urea nitrogen level increased 2 ± 4 mg/dL (P<0.001). Serum total cholesterol level decreased 11 ± 26 mg/dL (P = 0.006), low-density lipoprotein cholesterol level decreased 10 ± 25 mg/dL (P = 0.01), triglyceride level decreased 56 ± 45 mg/dL (P<0.001), high-density lipoprotein (HDL) cholesterol level increased 10 ± 8 mg/dL (P<0.001), and the cholesterol/HDL cholesterol ratio decreased 0.9 ± 0.6 units (P<0.001). There were no serious adverse effects, but the possibility of adverse effects in the 10 subjects who did not adhere to the program cannot be eliminated. Conclusion A very low carbohydrate diet program led to sustained weight loss during a 6-month period. Further controlled research is warranted.