.  I have always believed that the body regulates itself and that the body may tolerate some weight loss but that it will switch on something in your brain to make you crave sweets and food whether you want them or not in an attempt yo get your body back to the way it usually is...I think the body and brain is comfortable with the body being at a certain weight and is constantly fighting with you to get back to weight you were originally at....explains my yo-yo weight gain...it can't be just individual will power because then there would be more weight loss successes  