I practiced emergency medicine for 20 years until I developed obesity and a metabolic syndrome. At 5' I was up to 165# maximum or a BMI of about 33. After leaving emergency medicine and achieving a more normal lifestyle and sleep wake cycle, I committed to eating less and refining the quality of my diet in 1997. I also became certified as a nutritionist and fitness professional. I committed to walking daily and spending at least 10" on a row machine five days a week. I was able through caloric restriction and adoption of a more normal lifestyle to reduce my weight to 128#. I am now 65 and my weight has remained stable. I am sorry to disagree with you but basic science identifies the caloric intake needed to match a given energy expenditure and below that intake there is likely to be a loss in body mass. There are too many healthy thin athletic people in the world to focus on metabolics that may not be certain in those who are obese. I also worked in a refugee camp in the Horn of Africa during the drought and famine of 1985. When you have a starved infant with multiple infections die in your arms it becomes clear caloric restriction causes weight loss!