FutureShape Family

The number of adults and children living with obesity is increasing worldwide. Once childhood obesity has developed, more than 80% of children carry the obesity into adulthood, with a high risk of cardiometabolic disease, poor mental health, and decreased life expectancy. Parental obesity is a strong predictor of intergenerational obesity and is closely associated with a child's body composition from childhood through to adulthood. Obesity pharmacotherapy effectively reduces body weight. In adults, we have shown that combining obesity pharmacotherapy with supervised exercise improves weight-loss maintenance compared with pharmacotherapy alone. Emerging evidence suggest that exercise may also limit weight regain after treatment cessation. Together with evidence linking physical activity, sleep, and eating behaviours to weight regulation, these findings support combining pharmacological treatment with interventions targeting multiple modifiable behaviours. Personalised, data-driven feedback may further facilitate sustained behavioural change, but few interventions have integrated these approaches within the family setting. This 58-week randomized clinical trial aims to investigate the separate and combined effects of a data-driven, multimodal family-based intervention and semaglutide treatment for parents with obesity on body fat percentage and other health-related outcomes in parents and children. Approximately 400 families will be randomly assigned to one of four groups combining data-driven, multimodal family-based intervention or standard health advice with semaglutide or placebo. The data-driven, multimodal family-based intervention focuses on physical activity, diet, sleep and mental well-being. The trial will include families with at least one parent with obesity and at least one child aged 5 to 12 years with overweight or obesity. Participating parents with obesity will receive semaglutide or placebo once weekly for 28 weeks. The main outcomes are changes in body fat percentage in participating parents and children. Other outcomes include changes in body mass index (BMI) in parents and age- and sex-adjusted BMI, known as BMI z-score, in children. Families will participate in the main trial for 58 weeks and complete an additional follow-up assessment at week 104 after randomization.

Inclusion Criteria: * Family living in the same household with at least one Index Parent and one Index Child living with overweight/obesity (see below). * Written informed consent from all adult participants (age ≥18 years), participants between the ages of 15-17 years, and from the parental authority of the children (age \ +1 BMI z-score (\>85th percentile) for age and sex assigned at birth). Other members of the household: • All other members (non-Index parent(s) and non-Index child(ren)) of the household are invited to be included in the study and participate partly by wearing an accelerometer, wrist-worn activity tracker (e.g., a smartwatch), physical activity testing, answering questionnaires, and measurements of weight and body composition. Exclusion Criteria: * Known serious chronic conditions, including type 1 or 2 diabetes * Known medical conditions that hinder physical activity to a significant degree. * Treatment for cancer at screening other than oestrogen antagonist therapy or non-melanoma skin cancer. * Known severe psychiatric disease, a history of major depressive episodes, or other serious psychiatric disorders. * Known diagnosis or treatment for an eating disorder within the last 6 months * Known medical conditions or use of medication significantly affecting growth (Index Child) or causing clinically significant weight gain or weight loss (Index Parent(s) or Index Child) within the last 6 months before screening. * Bariatric surgery and weight-related surgeries (e.g., gastric bypass) within the last two years. Relating to semaglutide (Index Parent(s)) (according to the SmPC: https://www.ema.europa.eu/en/documents/product-information/wegovy-epar-product-information\_en.pdf) * Hypersensitivity to the active substance (semaglutide) or to any of the excipients used (Disodium phosphate, dihydrate, sodium chloride, hydrochloric acid, sodium hydroxide, propylene glycol, phenol). * Known severe renal impairment (eGFR \