We love the idea of group suffering, of 'all being in this together', of being comforted by being pitched 'en masse' in the mighty battle of weight. We laugh and poke fun at our "bad" habits. We satisfy a basic human need of hating to be different, so we hang out with 'people like us.'

We know for a fact that overweight parents are much more likely to have overweight children suggesting that future efforts to curb obesity should focus on parents. Modelling the behaviour of others is a common and natural part of being human so it's important, for example, that parents 'model' to their children that exercise is fun, not a tortuous punishment to be endured in the fight against excess weight.

I've always been intrigued by the fact that it is usually a pre-requisite for slimming group leaders to have previously been overweight themselves. I guess we think that this helps with empathy and in their understanding of the enormity of the weight loss challenge ahead. We feel comforted that this leader can truly relate to our plight. Why? Would you only go to a divorce lawyer who had been through that process themselves? Would you only put yourself at the mercy of a surgeon who had previously been under the knife himself?

In running my weight loss consultancy it is my experience that overweight people gain the most valuable information from spending time with naturally slim people. And - first of all – let me offer my definition of naturally slim. By this I mean a person who naturally (or effortlessly) balances calories in with calories out. In my experience these are people that invariably eat only in response to hunger. If you are struggling with weight issues it is vitally important that you devote a whole bunch of time to modelling – to copying the behaviours of slim people. It's always a real eye opener.

Friends are undoubtedly good for your overall health, Dr Christakis explains. So why not make friends with a thin person and let the thin person's behaviour influence you?