The primary objective of this multicenter randomized controlled trial is to evaluate treatment effectiveness of intervening simple obesity people with catgut implantation at preferred acupoints, which excludes placebo effect; the secondary objective is to evaluate safety and superiority of treating simple obesity with catgut implantation at acupoints to provide high-level evidence for it clinically.

This randomized, double-blind sham-controlled clinical trial will be conducted at Hubei Provincial Hospital of TCM, Dongzhimen Hospital Beijing University of Chinese Medicine and the First Hospital of Hunan University of Chinese Medicine. This study includes the following time points: a treatment period of 16 weeks after screening and a follow-up period of 24 weeks. The total study period will be 40 weeks. All patients will be randomized into the real catgut implantation at acupoints group or the sham catgut implantation at acupoints group.The primary outcome measurement of this study is the rate of waistline reduction compared with baseline. The secondary outcome measurements are the rate of reduction of weight, BMI, hipline, WHR and PBF, and changes in the IWQOL-Lite compared with baseline. These parameters will be evaluated at week 0, week 4, week 8, week 12, week 16, week 28 and week 40. Changes in SF-36, HAD and SES compared with baseline will be evaluated at week 0, week 16 and week 40. SF-36 and IWQOL-Lite will be used to evaluate obese patient quality of life. HAD and SES will be used to evaluate psychological status. In addition, hepatorenal function, blood fat, liver bladder spleen colour ultrasound, FBG and insulin concentration will be used to evaluate whether catgut implantation at acupoints can improve the physiological function of obese patients.

Inclusion criteria

Patients recruited for this study should meet the following inclusion criteria:

1. meeting the diagnosis standard for simple obesity in Redefinition and Processing of Obesity in Asia & Pacific Area released by WHO in February 2000;
2. age: 18-45;
3. BMI: 25≤BMI<30;
4. waistline: males ≥95 cm; females ≥85 cm;
5. smokers have not changed their smoking habits for at least 2 months;
6. willing to accept the above-described intervention methods.

Exclusion criteria

Patients with any of the following criteria will be excluded from the study:

1. endocrine disease (such as polycystic ovarian syndrome, Cushing's Disease, and hypothyroidism, among others);
2. gestational diabetes or uncontrolled hypertension (SBP ≥160 mmHg; DBP ≥100 mmHg) [23], or lung, heart, liver or kidney disease;
3. nervous system disease or mental disorders, history of hospitalized depression, two instances of paralepsy or suicidal tendency;
4. history of clinical diagnosis of an eating disorder , such as bulimia or cynorexia, anorexia; or weight changes greater than 5 kg in the previous 3 months;
5. history of weight loss with surgery or a history of post-operative adhesion;
6. having taken drugs with a known influence on weight or appetite in the previous 3 months, such as diet pills, corticosteroid drugs, anti-depression drugs, diazepam drugs, nonselective body antihistamine, nicotine replacements, or hypoglycaemic drugs, or planning to give up smoking and drinking;
7. pregnancy, lactation, or planning to become pregnant within 40 weeks;
8. received catgut implantation at acupoints;
9. participated in clinical research on obesity in the previous 3 months ;
10. protein allergy and scars;
11. skin disease such as eczema and psoriasis;
12. coagulation disorders, taking warfarin, heparin or other anticoagulant drugs;
13. not cooperative or cannot maintain treatment during the study period.

the data will be published in the form of public papers before May 2019 for public inquiries