Is fat bad?
Body fat is not a bad thing, it’s necessary and normal – we need it for energy and water storage, insulation, support and protection of organs, proper reproductive and immune system function. It’s also a strong sexual symbol. A healthy woman might have 25-35% of her body composed of fat – think about that - ONE QUARTER TO ONE THIRD!
It is very important that we have enough fat on our bodies. People without enough body fat are ILL – women are infertile, males and females are at higher risk of death (e.g. from infections) and of osteoporosis. Because of this, our bodies have developed complex systems to make sure that we have just the right amount of body fat. Unfortunately, these can go wrong…..
Why are people fatter now than in the past? It must be environmental, rather than a genetic effect because genes can’t change that fast….
We are the first generation to live with such an abundance of food (especially during the winter). Stone age people had no access to supermarkets, high calorie prepared foods or fast food restaurants Also, we don’t need to use as much energy to actually get food nowadays – not too much hunting and foraging in our modern lives.
Our bodies evolved in a very different environment: it used to be that we needed to be very motivated to find food so we have strong reward systems to encourage us to do this. In the distant past, those people who sought out the most food, ate the most calories and stored the most energy in their bodies (i.e. tended to get fat) were the ones who survived harsh times. In that environment, they (we) would be the healthiest people around and the most likely to reproduce. So, any small “normal” gene sequence differences that reinforce eating behaviour or increase fat storage would tend to be common in the population. These are not “bad” genetic variations – we have champion stone-age survival genes!
Our environment is now very different, but our bodies are still the same. Unfortunately, in...