Why should the RAF be interested about peoples long term health?
From a purely "bean counters" point of view, once you leave you become nothing more than a financial burden (assuming you have qualified for a pension, or even part pension). RAF pensions are funded from the MOD budget, not from general government funding. To a certain extent, the shorter your life span after leaving the RAF, the more money the RAF saves!
The same applies to the UK government as a whole, although the cost arguments on money saved by citizens life expectancy reducing (in terms of saving on pensions) vs increased costs incurred by the NHS having to deal with an unhealthy population is not one I am familiar with - although no doubt someone in the treasury has done/does this calculation on a regular basis.
Smoking is a similar situation. I believe (standing by to be corrected) that the taxes raised on smokers outweigh the financial cost to the UK economy of smoking related illnesses. Hence why the politicians haven't just banned it outright.