Muscle cells memorize obesity

BEIJING, Oct. 13 -- US researchers now think they know why obese people often fail to keep losing weight despite cutting down the calories.
The scientists from Duke University Medical Centre said the skeletal muscle of severely obese people was "programmed" to amass fat. The muscle bears a metabolic memory of obesity.
"The cells of obese people remembered their metabolic programme, which could help explain, in part, why losing weight and maintaining weight loss is so difficult," senior researcher Dr. Muoio said.
The study, which apprears in the journal Cell Metabolism, said exercise might be more successful in overriding the muscle's memory than a calorie controlled diet.
"The good news is it's possible to change your energy balance through exercise. Exercise can enhance muscle's ability to burn fat," Dr. Muoio said.
The researchers examined muscle removed from lean and obese patients during surgery.
They found that the fat-building enzyme called stearoyl-CoA desaturase-1 (SCD--1) was three times more abundant in the muscle taken from obese people than the muscle taken from thinner patients.
The researchers said this demonstrated an important link between obesity, diabetes and abnormal fat build-up in muscle.
The scientists said that the evidence suggested that diet during critical periods of development could lead to metabolic adaptations that persisted into adulthood in muscle memory.
"While these findings may be somewhat discouraging news for those wishing to reverse obesity through dietary interventions, they also highlight the importance of exercise," Dr Muoio said. Enditem