Is any difference in effectiveness of behavior modification and operant conditioning for weight loss?

The approach...: Both are forms of "behavoir modification"; and if you and your physician feel this is going to help you achieve your weight loss goal than go for it. I believe in a more traditional approach(diet modification(cut out white flour/sugars), 3-4 times/week of moderate activity(like walking; or other low impact activity) and just drink water ([8]-8 ounce glasses/day). Best of luck to you!

Done right both work: Operant conditioning is a form of behavior modification. Behavior modification is based in part on these basic principles: if someone receives what is considered a reward after engaging in certain behavior, that behavior will be strengthened or occur more often. If someone receives no reward, that behavior will weaken or occur less often. It is up to you to set up what behaviors get what rewards.