Researchers found that successful weight losers had significantly higher resting sympathetic nerve activity than those who had trouble shedding pounds. They also found that successful weight losers showed large increases in nerve activity after they ate a carbohydrate test meal. This did not occur in those who were weight-loss resistant. I have seen patients whose metabolism picked up after we fixed their adrenal glands and they lost weight without any changes in activity or diet.
Source: February 2012 issue of the Journal of Clinical Endocrinology & Metabolism.