Diet interventions
Participants in the NC group were designed to follow a non-restricted calorie diet with 55–65% of calories from carbohydrates, 30% from fat, and 20% from protein. The CR diet group restricted daily calories to 1200–1500 kcal/day with 55–65% of calories from carbohydrates, 30% from fat, and 20% from protein. Participants in the LC group were instructed to follow a non-restricted calorie diet with 26% of calories from carbohydrates, 50% from fat, and more than 24% from protein. The LC + CR group was instructed to restrict daily calories to 1200–1500 kcal/day with 26% of calories from carbohydrates, 50% from fat, and more than 24% from protein. Participants in the LC and LC + CR groups were provided with one nutritional bar (Nanda Fit Nutrition and Health Consulting Co., Ltd., Guangzhou, China) as the low-carbohydrate replacement at lunch and dinner and were instructed to consume low-carbohydrate grains, vegetables, fruits, and legumes. All the aliments were in accordance with dietary guidelines and previous studies for macronutrient intake [All the participants were instructed to photograph the food they ate and write a daily dietary log to record macronutrients, nutrition labels, and detailed dietary recipes 3 days per week (including 2 working days and 1 weekend day). Using each participant’s log and their photographic identification of the food they ate, two researchers assessed participants’ nutrient intake on the basis of the nutrient content listed in the Chinese Food Composition Table [