BBC’s Horizon examines this phenomenon further by running a clinical trail on a group of young adults who appear to be able to eat as much as they want and never put on weight.

This trial was done in a bid to examine the rising obesity problems of the West, with hopes of new and ground breaking theories as most of the trails and tests on obesity have been done on already obese people.

This group of your adults where required to eat a staggering 5000kcal per day, more than double the daily intake of calories the average woman should consume. Tested, probed and prodded each week for a grand total of 4 weeks, the findings were conclusive only in so far as we all have different responses to food and a lot of those responses may be down to genes. For the most part all the candidates increased in body weight but interestingly how these calories were processed by the body differed greatly.

Some of the candidates increased body fat percentage but gained very little weight, some the candidates had the reverse, one particular candidate actually increased his basal metabolic rate which means he increased muscle mass and at least a couple physically could not consume the calories in full for the entire period, their bodies put up various road blocks signs by way of increased gag reflexes and the like.

A further little experiment was done on some 4 year olds in a bid to establish how early on our eating habits and overfeeding begins, by providing a colouring activity and  placing an array of chocolates and chocolate biscuits in front of children they established were full up, they examined the responses to the treats in front of them.

Some children steadily ate the treats while some actively coloured and ignored the treats, question is, did the children eat these only because it was chocolate and did the ones that didn’t, perhaps not like chocolate? Is there a Psychological element of being given the treats, therefore by eating, the child is simply following instruction? One of the most interesting yet depressing theories to come out of this programme, is that our bodies determine what weight it wants but at what age that is determined is a  mystery, there may be some truth in the old wife’s tale that reads ‘the body you are at 30 is the body you remain’.

All the candidates got back to their normal sizes two weeks after the trials were over with no exercise or special diets. I would like to throw in a humble theory of hypo thyrodism, subclinical or otherwise and the consequential decreased metabolism amongst other things, there simply are many factors that can affect our thyroid function such as fluoride and high levels oestrogen both easily available in the water we drink, could there just be  a lot more of us walking round with low thyroid function than we realise?