My husband has this problem and he is extremely addicted to coffee. He is also steadily losing weight at about 2 lbs a week. If he was 300 lbs this would be ok, but he only weighs 142 right now. He is also 77 yrs old and I'm concerned about the weight loss. He has been tested for cancer and thyroid issues and they have found nothing. Could the excess body heat be making him lose weight?