We are designed to seek food – our drive to do so is essential to our survival and we have a complex system to control this. Recent research shows that following weight loss, levels of circulating hormones which affect our appetite tend to promote over-eating and weight regain.
Indeed, the Minnesota experiment published in 1950 showed that we tend to overeat after a period of energy restriction until fat mass has returned to or exceeded initial levels. And although we might consider fat a simple energy reserve, during periods of food shortage fuel partitioning is not straightforward – muscle protein is just as readily converted to energy which protects fat stores.
Blame the Hunter-Gatherers
It can be surprising to hear that excess fat is rigorously defended by our own bodies. However, a moment’s thought explains why this should be. Our physiology has been shaped over millennia by evolutionary processes which make us suited to a hunter-gatherer lifestyle – which necessitates high levels of physical activity and likely periods of famine and feast.
