You do not see many prime athletes at fat clubs. However, prime athletes are very much in the same boat when it comes to their main aim. Bodyfat levels are key to performance at optimum, world record standard, as they are for the laymen. Whatever the motive behind the goal, losing bodyfat is universally desired by the range of people involved.
The key is discipline and a willingness to change.
Change is the hardest thing to do, because it usually meets with all sorts of resistance from the lifestyle you are moving away from. Lifestyle is bound by hidden and subconscious conditions to which we are attached. Social, moral, religious, traditional, learned behaviour that we can't easily stop.
Other behaviour may relate to obligations such as family, work, social, or other activities involving other people. These engagements can start to trap us. No matter how much we want to be slimmer, our behaviour is not ruled and governed by the needs of our waistlines.
Unfortunately, if you want the results badly enough, you must push the priority of the waistline ahead of all others. That includes work, family and society. The first and last person in your life is yourself, and you get one body, yours. So unless someone else is going to run your 40 minute cardio session tomorrow morning, then someone else can drink that large vodka and coke themselves.
Unless she wants to come shopping with you and pay for the next size up, then they can eat the cheese and onion pasty herself this lunchtime. The good thing fat clubs do is change behaviour in favour of the fat burning system of the human body. It changes people, through education, group motivation and other methods.
In that sense, while the means are questionable, the end result is a change of mind in the person. And, until that person changes their mind, through education, adopting and activating appropriate eating, nothing will happen. Ask anyone, from obese to athlete, about losing bodyfat, and they will tell you that it isn't easy. It requires a break from "normal" behaviour. Unfortunately, as the heart disease statistics prove, "normal" behaviour in the western world is hugely unhealthy for a growing population.
Choose your own path, put your trainers on, and walk it. Anyone who questions it is not, ultimately, FOR you.