Low Carbohydrate & Low Fat Diets the Same for Weight Loss

Many claims in lay media and scientific literature have been made regarding the superiority of a certain diet for inducing weight loss.  Two recent studies one published in the Journal of the American Medical Association and the second in Annals of Internal Medicine found that using either a low-carbohydrate or low-fat diet had the same end result. The best diet is that which works best for the dieter.

http://jama.jamanetwork.com/article.aspx?articleid=1900510

Johnston et al report in JAMA finding from their search of 6 electronic databases based on which they estimated the relative effectiveness of diets to affect weight and body mass index from baseline.  Weight loss and body mass index was determined at 6- and 12-month follow-up.

Among 59 eligible articles reporting 48 unique randomized trials that included 7286 individuals, the largest weight loss was associated with low-carbohydrate diets 8.73 kg at 6-month follow-up and 7.25 kg at 12-month follow-up and low-fat diets 7.99 kg at 6-month follow-up and 7.27 kg at 12-month follow-up. Weight loss differences between individual diets were minimal. For example, the Atkins diet resulted in a 1.71 kg greater weight loss than the Zone diet at 6-month follow-up.

They concluded significant weight loss was observed with both low-carbohydrate or low-fat diet. Weight loss differences between individual named diets were small.

http://annals.org/article.aspx?articleid=1900694

In the study by Bazzano et al published by the Annals of Internal Medicine, the effects of a low-carbohydrate diet compared with a low-fat diet of on body weight and cardiovascular risk factors was determined.

148 men and women without clinical cardiovascular disease and diabetes were placed on a low-carbohydrate (<40 g/d) or low-fat (<30% of daily energy intake from total fat [<7% saturated fat]) diet.

Data on weight, cardiovascular risk factors, and dietary composition were collected at 0, 3, 6, and 12 months.

Sixty participants (82%) in the low-fat group and 59 (79%) in the low-carbohydrate group completed the intervention. At 12 months, participants on the low-carbohydrate diet had greater decreases in weight (mean difference in change, −3.5 kg), fat mass (mean difference in change, −1.5%), ratio of total–high-density lipoprotein (HDL) cholesterol (mean difference in change, −0.44), and triglyceride level (mean difference in change, −0.16 mmol/L) and greater increases in HDL cholesterol level (mean difference in change, 0.18 mmol/L) than those on the low-fat diet.

They concluded low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet.

Based on these studies both low-carb and low-fat diets induced weight loss but there was not a sizable differences between the two. Finally, the branding of the diet did not have an impact on weight loss.