Sex differences in the associations of sleep-wake characteristics and rest-activity circadian rhythm with specific obesity types among Hong Kong community-dwelling older adults

•Circadian rhythm fragmentation was related to obesity and muscle loss.•Delayed sleep-wake cycle was associated with obesity in male older adults.•Males with delay onset of peak activity had higher adipose outcomes.•Lower relative amplitude was linked to higher BMI and lower hand-grip strength.•Prolong sleep hours associated with lower muscle strength regardless of sex.