No, no, & no again.
It is impossible to compare apples against orange, big or small, RAF or CFAV.
That also ignores the floodgates that would open for CFAVs leaving the organisation.
Yes, in general society it would be better for the world to be healthie****, for our NHS to be able to reduce their expenditure on obesity-related treatments / conditions / equipment (bariatric ambulances, etc), & for children not to be taken into care / put on risk register as their parents are feeding them like geese for foie gras!. Now, when it comes to taking mandatory / legislated action against members of the population for being obese, such as reduction in tax credits, benefits, surcharge for health care, then there might be the faintest chance of some kind of health push for volunteers. Oh, that won't happen in the next 50 yrs, despite the fact that the UK statistics are not "healthy."
*** = needs an actuary type of mind to play with the figures, die earlier = less health care costs to the state / less pension costs to pay out....... A study some while ago suggested that if smoking in UK was banned completely, tax revenues would drop, but gradually NHS costs would decrease due to health improvements, more or less cost-neutral. However, the extra life expectancy would negate this, as pension costs would increase. Overall, it would end up costing more!