Obesity is on the increase. Once, there was a direct link between wealth and obesity; but as the Western world develops and we all become richer, that link has been broken down and now weight problems can affect us all. The prevalence of this condition has led academics and researchers to explore the complexities of the problem in attempt to ascertain the root causes of the problem.
We also physically mature faster than we once did, and new evidence suggests that early maturation has links to obesity later in life.
In general, we take less exercise than we once did, we eat more 'fast food' and we serve larger portions of food. Food is cheaper now than it was – especially luxury foods, which are available cheaply and in most shops. These are undoubtedly the keys to the problem: we are consuming more calories and converting fewer of them into energy for exercise.
There are various diseases and prescription medications that can result in weight gain; and depression is just one example of a mood disorder which can lead to overeating. (It is known that depression is also on the increase, but it is not clear whether these phenomena are related.)
Many scientists believe that there may be a link between tendencies to put on weight and our genetic make-up. The National Obesity Forum have put the number of genes currently under investigation at 250, and GAD2 is just one of them. This gene has been investigated by Imperial College London, and it is believed that it comes in two forms: one which increases the appetite, encourages overeating and is usually found in overweight or obese people, the other which decreases the appetite and is usually found in thin or underweight people. Research into the role of this gene, and hundreds of others, in weight gain continues.