Are Pre-obese People Energy Thrifty?

Metabolic rate and fat-free mass tend to be higher in obese people than in lean people. It has been suggested that pre-obese people have a low metabolic rate and only acquire their high metabolic rate from the storage of lean tissue which they gain while becoming obese. To test this hypothesis resting metabolic rate was related to percentage fat, with fat-free mass held constant, in 104 women with body fat ranging from 6% to 60% of body-weight. Results showed that the greater the percentage fat, the greater the metabolic rate. It is difficult to believe that fat people with a high metabolic rate relative to fat-free mass once had a low metabolic rate.