Poor patient compliance and Withdrawal of support from the exercise training institution

This controlled clinical trial aims to compare the effects of an online program that includes exercise guided by the FITT-VP principle and dietary advice, conducted by fitness coaches, in children and adolescents with obesity with a control group that will be enrolled in conventional in-clinic nutrition and exercise advice. All participants will be monitored for 8 months during the active intervention, and followed by 16 months of observation.

The study will evaluate the following parameters between groups: BMI, anthropometry, blood biochemistry panel (ALT/AST, lipids, uric acid, HOMA-IR, HbA1c), food frequency questionaire, household survey, satisfaction survey, and adverse events.

Inclusion Criteria:

1. Simple obesity: Body mass index (BMI) between +2SD and +3SD of the reference range: based on the "Standard Deviation Curve of BMI for Children 0-18 Years of Age in China", which was developed by the Physical Development Survey of Children in Nine Provinces/Cities in 2005;
2. Not participating in other weight management programs currently or in the 3 months prior to the study;
3. Accepts to participate and signs informed consent.

Exclusion Criteria:

1. Currently taking or planning to take medications or interventions that affect body weight during the study period (32 weeks)
2. Obesity caused by other medical conditions. For example, hypothalamic-pituitary disease, hypothyroidism, growth hormone deficiency, Cushing's syndrome, obesity-related syndromes.
3. Comorbidity with other chronic diseases. E.g. psychiatric diseases, respiratory diseases, gastrointestinal diseases, rheumatic diseases, hepatic and renal insufficiency, chronic infectious diseases;
4. Presence of abnormal laboratory values at the time of screening indicating a clinically significant underlying disease or condition that may prevent the subject from participating in the study; or presence of abnormalities in the following laboratory tests: alanine aminotransferase (ALT) greater than 5 times the upper limit of normal, serum creatinine (Scr) greater than 1.5 times the upper limit of normal.
5. Contraindications to physical exercise or exercise-related risks. For example, history of asthma, history of hypoglycemia/diabetes, history of heart disease, history of cardiovascular disease, fracture/surgery/planned surgery within the last 1 year, psychomotor retardation, motor system defects/disabilities, previous history of exercise intolerance;