Objective: We examined the association between obesity and physical performance under different metabolic status.
Methods: The sample included 1395 Chinese community-dwelling participants (mean age, 71.88 ± 5.87 years; 40.9% men). Being metabolically healthy was defined as having the presence of < 3 of 5 components of metabolic syndrome (MetS); obesity was defined as having a BMI > 28 kg/m². Participants were divided into four groups based on BMI (non-obese/obese) and metabolic health (healthy/unhealthy). Physical performance was measured by grip strength, 4-m walking speed, and the timed up and go test (TUGT).
Results: After multiple adjustments, compared with metabolically healthy non-obese group, the metabolically unhealthy obese group showed lower relative grip strength, lower 4-m walking speed, and higher TUGT (P  all < 0.05), and only relative grip strength of the metabolically healthy obese group was significantly lower than that of metabolically healthy non-obese (P < 0.01). Relative grip strength was negatively associated with impaired fasting glucose (β = − 0.071), elevated triglycerides (β = − 0.062), abdominal obesity (β = − 0.230) and general obesity (β = − 0.225) (P  all < 0.01). Walking speed and TUGT were only associated with general obesity, rather than other metabolic components. The associations of MetS with physical performance were mainly driven by abdominal obesity.
Conclusion: Even in those who are metabolically healthy, obesity (especially general obesity) increases the risk of poor physical performance. Elderly people with general obesity and MetS, whether in combination or alone, have an increased risk of muscle dysfunction, and that combination produces a higher risk of impaired mobility.
Keywords: metabolic health, obesity, physical performance, grip strength, 4-m walking speed, TUGT