Exercise and protein during energy restriction in old obese (REPOWER)
Research type
Research Study
Full title
The effect of dietary protein intake on body composition and muscle protein turnover during a 4-week period of energy restriction and exercise in older adults with obesity
IRAS ID
338877
Contact name
Leigh Breen
Contact email
Sponsor organisation
Research Park, University of Birmingham
ISRCTN Number
ISRCTN13303580
Duration of Study in the UK
2 years, 0 months, 3 days
Research summary
An increased prevalence of older adults (>65 years) is accompanied with an increased prevalence of obesity among this population demographic. Although diet-induced weight loss is often prescribed to individuals with obesity, intentional weight loss can precipitate the decline muscle mass, muscle function, and physical performance in older adults, and thus increase an individual’s risk of physical disability. To understand in the role of protein and exercise during weight loss, we are conducting a randomised, parallel-groups study in older adults with obesity. The participants, males and females aged 65-80 years, will be recruited based on excess adiposity and overall health, ensuring their ability to adhere to the study requirements. Eligible participants will be randomly assigned to resistance and endurance exercise training with 1). energy balance and 0.8 g/kg BM/day total protein intake (EB-NP), 2). energy restriction and 0.8 g/kg BM/day total protein intake (ER-NP), or 3). energy restriction and 1.6 g/kg BM/day total protein intake (ER-HP). All groups will complete a 7-day lead in of energy balance prior to the intervention to establish a baseline. Participants will then undergo a 28-day intervention with exercise and variable energy intake and protein intake, according to their allocated condition. The primary outcome will be dual-energy X-ray absorptiometry (DXA) and bioelectrical impendence analysis (BIA) derived lean body mass before and after the 28-day intervention. Secondary outcomes include skeletal muscle protein synthesis, muscle strength, physical performance, and aerobic capacity. Thus, we aim to determine the effect of a higher protein intake on lean body mass and myofibrillar protein synthesis during a 4-week period of energy restriction and combined resistance and endurance exercise training in older adults with obesity.
REC name
West Midlands - Solihull Research Ethics Committee
REC reference
24/WM/0095
Date of REC Opinion
5 Jun 2024
REC opinion
Further Information Favourable Opinion