This study is testing how different types of protein - from red meat, legumes (like lentils and beans), or a mix of both - affect muscle strength, body composition, and metabolic health in older adults with obesity who are also at risk for sarcopenia (loss of muscle mass and function). Participants will follow a personalized weight loss diet with one high-protein meal each day that includes either red meat, legumes, or both, along with a home-based strength training program. The study will last three months and will include health assessments such as blood tests, muscle and fat measurements, and physical function tests. The goal is to find out which type of protein source is most helpful for improving strength, reducing body fat, and supporting healthy aging.
Aged 55 years or older.
Diagnosed with obesity.
At risk for sarcopenia, based on at least one of the following: Low score on the validated SARC-F-calf questionnaire (as suggested in prior studies). More than one comorbidity associated with sarcopenic obesity (e.g., diabetes, osteoporosis, cardiovascular disease, etc.). Polypharmacy: taking 8 or more prescribed medications. Evidence of strength or functional impairment, assessed using validated measurements at the baseline visit.
Recent use of steroid agents within the past 6 months (replacement therapy is allowed).
Uncorrected hypothyroidism: TSH > 6 mIU/L.
Diagnosis of malignancy within the past 5 years, except for non-melanoma skin cancer.
Chronic kidney disease (CKD) at stage >1 (due to protein restriction needs).