Scalp Hair Metabolomics in Severe Obesity

The investigators will recruit 30 subjects with severe obesity scheduled for bariatric surgery and 30 healthy-weight controls.

Following written informed consent, the investigators will collect the study subject's medical information, conduct a dietary and quality-of-life survey, take body measurements, obtain scalp photos, perform a hair-pull test, collect a hair sample, and conduct muscle strength testing. Controls will be assessed only at baseline. Those with severe obesity will return at 4 ± 2 weeks, 12 ± 4 weeks, and 26 ± 4 weeks following bariatric surgery to repeat the study procedures.

Inclusion criteria

All subjects:

• Age 21-70 years
• Ability to provide informed consent

Healthy weight controls:

• BMI of 18.5-24.9 kg/m2
• No chronic disease
• No long-term medications

Severe obesity:

• BMI of > 32.5 kg/m2
• Scheduled to undergo bariatric surgery

Exclusion criteria

• Pregnancy
• Any factors likely to limit adherence to study protocol
• Any history of autoimmune or scarring alopecia (eg. alopecia areata, discoid lupus, lichen planopilaris)