They should have gone with a different angle.
- Incentivise cheaper membership for people with a 'weight problem'. Financial motivation.
- Provide evidence of a comfortable environment for people to exercise without feeling judged or stupid.
- Offer personalised help and motivational support from employees.
Putting on weight is 100% down to diet, exercise will never be the difference between being overweight and being in good shape. It's all diet.
With that in mind, why should people who are overweight be subsidised by people who eat sensibly? They're already subsidising overweight people who will use the NHS more. Also not sure if you've noticed, but people who are overweight tend to take more sick days off work, so people who bother to keep themselves fit and healthy also have to pick up their work load.
So based on that, wouldn't it be fairer if people who are in shape get a gym discount and tax breaks rather than the other way round?