The study involved 245 generally healthy, non-obese participants between the ages of 18 and 35 in a six-month randomised controlled-feeding trial. The participants were split into three groups, one of which was put on a low-fat, high-carbohydrate diet, another on a moderate fat, moderate carbohydrate diet, and the last on a high-fat, low-carbohydrate diet.
Their individual body weight was measured at the end of each month, and at the end of the trial, the group on the low-fat, high-carbohydrate diet showed better results than the other two: “Reduction in waist circumference, total cholesterol, low-density lipoprotein (LDL) cholesterol and non-high-density lipoprotein (non-HDL) cholesterol in the lower fat, higher carbohydrate group were greater than those observed in the other two diet groups.”
The study further stated that “while all three dietary interventions were associated with decreases in weight, waist circumference, level of total, LDL, and non-HDL cholesterol”, reductions in the low-fat, high-carbohydrate diet group were greater than those observed in the other two groups.
This is contrast with the belief that in North America and certain parts of Europe, a high-carbohydrate but low-fat diet has contributed to the obesity epidemic. In China, the shift away from low-fat, high-carbohydrate diets — which are similar in macronutrient composition to traditional Chinese diets — to a high-fat, low-carbohydrate one has coincided with the country’s rapidly rising obesity rates.
This suggests that “findings from studies in European and North American populations suggesting possible benefits of carbohydrate restriction may not apply to people of other ethnicities”.
Returning to tradition
According to the study, the results also imply that the traditional diet will probably be more effective in encouraging weight loss in the overweight and obese, and may also have greater potential than higher-fat diets to reduce the risk of unwanted weight gain in adulthood.
At the same time, considering the profile of cardiometabolic risk factors measured on the three diets, the traditional low-fat, high-carbohydrate diet “characteristic of the dietary patterns in China” is associated with a reduced overall risk of cardiovascular disease, unlike the high-fat diets.
The study concluded: “Our findings, in conjunction with all other available evidence, suggest that the Chinese population should be discouraged from following the continuing trend towards increasing dietary fat intake at the expense of carbohydrates.”
“Effects of Macronutrient Distribution on Weight and Related Cardiometabolic Profile in Healthy Non-Obese Chinese: A 6-month, Randomized Controlled-Feeding Trial”
Authors: Yi Wan, et al.