I've just finished watching this programme, and there are three things that I took away from it.
Firstly, the gut hormone changes that occur with this form of surgery in contrast with simple gastric banding, which change the physical desire for food, so there is far less chance of relapse. This is a clear benefit to those who have it, and it is a clear cost benefit to the NHS with the reduction of future illnesses. Of that there is no doubt.
Secondly, it is the pernicious effect of CCGs that is rationing these treatments. These CCGs are an unnecessary and costly intervention in the passage of money to local health services. They don't exist in Scotland. This is a money thing. Preventing future health expenditure does not seem to drive cost benefit analysis in NHS England.
Finally, the one thing that was brushed aside, as in not mentioned at all, is that a completely redundant stomach remains sitting in the abdomen, where it can quietly grow a cancer to a completely inoperable stage without any symptoms whatsoever. It's not a common cancer - 7000 diagnosed every year, and symptoms are vague even in normal people- chronic dyspepsia, nausea, etc. so it often presents late in any event. This bariatric surgery makes sure it presents late and terminal. That'll lose weight even quicker.
Sorry to end on a downer, I thought this programme was very non-judgemental, didn't hammer the Diabetes thing, and made its points well.