Discussion
obese, weight loss
OBESE
In this multicenter study, we test the hypothesis that a reduction of carbohydrate intake without restricting caloric intake was more effective on weight loss when compared to a calorie-restricted diet in overweight/obese adults. Our findings align with some previous studies. Samaha et al. [Our results indicated that a low-carbohydrate diet alone without calorie restriction is sufficient to improve body weight, waist circumference, and body fat when compared with a calorie-restricted diet after a 12-week intervention. Evidence indicates that weight loss via lifestyle modification is largely mediated by energy intake rather than energy expenditure [Several clinical trials assessed the effects of low-carbohydrate diet and calorie-restricted diet on waist circumference and body fat among obese patients. Bazzano et al. [In this trial, only a low-carbohydrate calorie-restricted diet significantly reduced serum triglycerides during the 12-week intervention while other diets had no effect on lipids. In contrast, Samaha and colleagues [This study has some limitations. Firstly, the results presented in this analysis provide data only on short-term changes, maintaining weight loss and accompanying improvements is challenging. Whether differences between diets persist in the long term still needs to study. Secondly, the provision of nutritional bar might affect adherence, which might have biased the results. However, adherence to diet intervention did not differ between these groups. Thirdly, physical activity was not strictly controlled in this study because we aimed to examine the isolated effect of low-carbohydrate and calorie-restricted diets on weight loss. Finally, objective biomarkers of energy and macronutrient intake are lacking. Stronger weight loss with LC diet than CR diet despite higher calorie intake with LC is surprising and requires follow-up in controlled biomarker studies. Energy expenditure measured by the double-labeled water method may help to explain the differences among patients in weight loss in response to the diet interventions.