Is any difference in the effectiveness of psychotherapy and behavior modification for weight loss?

Therapy & wt loss. The question is difficult to answer because behavior modification is part of psychotherapy, not an alternative to it. Effective weight loss involves maintaining normal eating patterns, exercise, social support, realistic weight goals, a focus on health rather than appearance, & good self-esteem. Effective programs are comprehensive, long term & address your specific obstacles to success.
Yes. Behavior modification is the process of determining why you participate in an unhealthy or self-damaging behavior and changing that behavior. Psychotherapists address the root cause of overeating so clients modify their behavior and lose weight which is another addition to weight loss program.