The study was designed to investigate the effects of a very low carbohydrate diet (VLCD) intervention on weight control in overweight/obese patients in China.All the subjects were randomly assigned to experiment group and control group. The experimental group was given individual instructions on how to follow the VLCD (very low carbohydrate diet). The control group was given an energy-restricted diet.The energy-restricted diet (ER diet) was designed in the traditional Chinese style with an initial target for a total energy intake of 1200 kcal/d (5021 kJ/d).

121 obese or overweight patients were enrolled in the study and 23 patients were dropped out (43 male, 55 female, aged≥18 years, BMI≥24 kg/m2) from the outpatient clinic of endocrinology and metabolism department of Southern Medical University Affiliated ZhuJiang Hospital. All the subjects were randomly assigned to experiment group and control group. The experimental group was given individual instructions on how to follow the VLCD (very low carbohydrate diet). Energy intake was restricted to less than 800kcal/day (3349kJ/d) (carbohydrate intake < 20g/d). All daily meals were replaced as follows: a cup of soybean milk (200 mL) and a boiled egg at breakfast; a diet nutrition bar (106 Kcal: 2.8 g carbohydrate, 11.2 g protein and 5.6 g fat; Nutriease Health Technology Co., Ltd., Hangzhou, China), nonstarchy vegetables (<200 kcal), and 50 g protein from meat (i.e., beef, lean pork, skinned chicken, fish) at lunch and dinner. Supplementation of multivitamins and minerals was provided per day. The energy-restricted diet (ER diet) was designed in the traditional Chinese style with an initial target for a total energy intake of 1200 kcal/d (5021 kJ/d). Subjects were also encouraged to drink at least 1.8 litres of water per day, and asked to maintain their habitual level of physical activity. Compliance with the diet and physical activity level was checked at weekly visits.

Inclusion Criteria:

• overweight or obese healthy volunteers (43 male, 55 female, aged≥18years, BMI≥24 kg/m2)

Exclusion Criteria:

• pregnant or plan for pregnant
• lactation or postmenopausal women
• use of any prescription medication in previous 2 months
• had any weight loss diet or pill during the past 6 months
• consuming>20 g/day of alcohol
• tobacco use within 6 month
• cardiovascular or endocrine disease history
• hypertension history or current elevated blood pressure (systolic blood pressure (SBP): ≥150 mmHg; diastolic blood pressure (DBP)≥90 mmHg; current treatment for hypertension)
• diabetes mellitus
• acute or chronic infections
• hepatopathy, kidney disease, gastrointestinal disease or any other acute or chronic diseases requiring treatment.