I find it interesting that all of the standard problems that are tied in to obesity (diabetes, cholesterol, hypertension, etc) are all treated with pills, sometimes with fairly serious or dangerous side effects. My doctor always tells me to lose weight and that will help all these other things. But even through weight loss is the magic bullet, there is no attempt to help us lose weight other than "eat less and exercise more". In other words, willpower. I know in the past they used to have appetite suppressant pills and other things that didn't work, but I haven't heard anything about any newer weight loss aids. It seems that if they want us to lose weight, there might be something they could do to help. It's almost as if the profits from treating the diseases are more important than actually solving the problem...no, it couldn't be.
I think your first sentence answers the question you almost ask in your last sentence. Docs get chastised for writing scripts that come with side effects, when in fact, the real solution comes in changing behaviors. The reasons we don't want to be obese is that we want a longer life, and a higher quality of life. Not because 150 is a better number than 210.
A pill that gets you to 150 but comes with nasty side effects does not provide a longer life, or a better quality of life. What WILL do that is to gently modify your diet (probably just avoid "seconds" and eat a veggie or two a day), and get just a wee bit of exercise ( walk briskly for 45 minutes a day)...
The pill may get you to a number. The number is meaningless.
I encourage you with every positive thought I can muster, to just take it in small steps...but steps in the right direction. There will never be a magic pill.