Inclusion Criteria:  Obese (BMI 30-40Kg/m2 and above) Aged 18-40 years Saudi nationality Female  Exclusion Criteria:  Age under 18 or above 40 years Any medical/endocrine problem that could affect energy expenditure (e.g. thyroid problems, Cushing's syndrome) Those with chronic inflammatory disorders like rheumatoid arthritis, or long term use of steroids or other immunomodulatory like cyclosporine, azathioprine; severe depression or any psychiatric illness, claustrophobia or needle phobia. Males Expatriates