Why Is It So Hard To Lose Weight?
We are designed to seek food our driving 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 circulate hormones which affect our appetite tend to promote over-eating and weight regain.
Indeed, the Minnesota experimentation published in 1950 demonstrating 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 dearth 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 few moments supposed explains why this should be. Our physiology has been shaped over millennia by evolutionary processes which build us suited to a hunter-gatherer lifestyle which necessitates high levels of physical activity and likely periods of famine and feast.
Those with thrifty metabolic adaptations, which preferred storage of excess energy as fat would have been more likely to survive and pass on their genes. During periods of famine, the ability to hold on to stored fat would also have been advantageous. These adaptations which were once useful, are now causing unprecedented levels of obesity across all populations that result a lifestyle characterised by low levels of physical activity and an abundance of food. In short, we are designed to store fat, and to keep it once we have it.
Designed For Fat
To understand our physiology, we must understand homeostasis whereby biological systems are governed largely via negative feedback systems. Changes to a monitored condition( such as body fat) render responses that oppose the change until the monitored condition returns to a situated phase. This seems to be the case for weight loss. A reduction of fat tissue outcomes in changes in levels of hormones that typically lead to a return to the original level of fat.
Crucially however, this does not seem to be the case when dealing with weight gain . Our biological systems seem insufficiently powerful to return us to our set-point. Perhaps the environment is too overwhelmingly obesogenic? Or perhaps our physiology has always relied on an external event, such as famine or high levels of physical activity, to regulate body weight?
As long as the environment remains obesogenic, the problem of obesity will remain. We can no longer rely on our instinct to govern body fat there is a need to rely on our intellect.
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