PHYSIOLOGICAL, NUTRITIONAL AND BEHAVIORAL EFFECTS OF A WEIGHT-NEUTRAL VS. A WEIGHT-CENTERED LIFESTYLE INTERVENTION IN OVERWEIGHT AND OBESITY: A MIXED METHODS STUDY

• Grant number: 24/18131-9
• Support Opportunities: Scholarships abroad - Research
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Health Sciences - Nutrition - Dietetics
• Principal Investigator: Fabiana Braga Benatti
• Grantee: Fabiana Braga Benatti
• Host Investigator: Mary Beth Weber
• Host Institution: Faculdade de Ciências Aplicadas (FCA). Universidade Estadual de Campinas (UNICAMP). Limeira , SP, Brazil
• Institution abroad: Emory University, United States

Abstract

Current literature supports the notion that group-delivered weight-neutral lifestyle interventions, which focus on improving patients' relationship with food, building awareness of hunger and fullness cues, and emphasizing pleasurable exercise and emotional and physical health over the pursuit of a lower weight or size, seem comparable or slightly superior to weight-centered lifestyle interventions in the treatment of obesity. However, the intensity and mode of which the intervention is delivered is of paramount importance to positive results. We have previously shown that an intensive, individually delivered weight-neutral lifestyle intervention was superior to a less intensive group-delivered one in overweight and obese women. However, we did not compare our intervention to an also intensive, individually delivered, but weight-centered lifestyle intervention, precluding the possibility of comparing the effectiveness of this type of intervention to the one still considered the cornerstone of obesity treatment. Thus, the aim of this research project is to comprehensively investigate the physiological, nutritional and behavioral effects of an intensive weight-neutral vs. an intensive weight-centered lifestyle intervention in overweight and obesity participants using a mixed methods approach. In this prospective, parallel-group, randomized controlled trial, participants will be randomly assigned (1:1) either to the intervention group (I-WN), which will consist of an intensive weight-neutral intervention or to the control group (I-WC), which will consist of an intensive weight-centered intervention. Both interventions will consist of biweekly individual nutritional sessions, group physical exercise sessions 3x/week, and 4 group workshops with psychologists throughout the intervention. Participants will be assessed at baseline (W0), at mid-intervention (W20), at the end of intervention (W40), and at follow-up (6 and 12 months after the end of the intervention - W66 and W92), for cardiovascular risk factors (insulin resistance, lipid profile, inflammatory markers, blood pressure and waist circumference), body weight and body composition, physical capacity and function, food intake, eating behaviors (eating attitudes, symptoms of binge eating, food cravings, cognitive restraint, uncontrolled eating and emotional eating, and appetite perceptions and gut hormones assessment), health-related quality of life, sleep quality, depression, self-efficacy, self-esteem and body satisfaction. Qualitative data will be collected via semi-structured focus groups which will occur at W40, W66 and W92, and will explore experiences, feelings and perceptions of participants regarding their eating practices, body image, and the intervention, thus providing a deeper understanding of the quantitative data.