I am on a low income but I don't have help to pay, I do it myself because i made the proactive choice to get healthy and shed the pounds. So I do see your point there. I also know that certainly in my area they have a scheme which is a little bit like an NHS version of WW, also a 12 week course of sessions with a weigh in each week, and you also get 12 weeks of membership of the local council sports facilities.
I do appreciate what you mean by the NHS funding something that could be paid for out of pocket, but dealing with the issues around obesity is fast becoming one of the nations biggest health risks. If you walk into the GP and say that you have tried everything and the GP says "Go to WW etc", without it being seen as treatment, I bet a fair proportion of the people wouldn't go. It was probably hard enough for them to walk into the GP and admit that they can't do this alone.
And much as it's wrong for them to be having to meet "targets" in the NHS, Medical staff will be under a lot of pressure to be cost effective. Say a gastric band op costs £5k. That helps just one morbidly obese person and may or may not be very effective long term, with no actual guarantee it will work. For the same money, you could send 100 people to a group like SW or WW for 12 weeks and if just a handful of those people manage to stick with it and lose some weight then overall that money had been better spent.
As I said, despite being on a low income I fund myself to go to group, and it does my selfesteem good because I am taking positive steps for me to feel better, no one made me do it, I just want to. I wouldn't be upset if someone that earnt good money got a 12 week pass, because they are still trying to do the same thing as I am doing, but their situation or medical need may be different.