The business model for gyms is based upon capturing the market for those who are obese and/or have poor self image, anorexics etc and those females in particular looking to tone up, move on, escaping boring, dead end relationships, so let's sell the gullibles the dream. Quite successfully if the truth be told and they do benefit some of the poor unfortunates.
They also provide a paid service to the NHS for those with clinically diagnosed conditions. In fact most of those mentioned, just not clinically diagnosed, yet!
If you didn't suffer from an OCD beforehand, you certainly will afterwards as recent surveys have shown.
Rule of thumb is, eat healthy and get regular exercise, keeping a well balanced lifestyle. Much better to do this for improving self confidence and self image than using a prop, as props do have a habit of breaking, or breaking you.
Now getting back to McKinnish, he certainly does need help in the obese stakes. Gym isn't working, nor is he living a healthy lifestyle, so the first weakness in his character. Last, but his biggest problem, hanging around with taigs, which of course could explain the obesity, as they always were a bad influence and sheep worrying is also a criminal offence.
So, if looking for a new manager, don't do one that is obese, does gyms, worries sheep or influenced by taigs, as clinically, he's well fucked and not the winnng formulae.