User:Mirandalee98/sandbox

Human bodies are predisposed to maintain homeostasis, especially when storing energy as fat. This trait serves as the main basis for the “thrifty gene hypothesis”, the idea that “feast-or-famine conditions during human evolutionary development naturally selected for people whose bodies were efficient in their use of food calories”. Hunter-gatherers, who used to live under environmental stress, benefit from this trait; there was an uncertainty of when the next meal would be, and they would spend most of their time performing high levels of physical activity. Therefore, those that consumed many calories would store the extra energy as fat, which they could draw upon in times of hunger.

However, modern humans have evolved to a world of more sedentary lifestyles and convenience foods. People are sitting more throughout their days, whether it be in their cars during rush hour or in their cubicles during their full-time jobs. Less physical activity in general means fewer calories burned throughout the day. Human diet has changed considerably over the 10,000 years since the advent of agriculture, with more processed foods in their diets that lack nutritional value and lead them to consume more sodium, sugar, and fat. These high calorie, nutrient-deficient foods cause people to consume more calories than they burn. Fast food combined with decreased physical activity means that the “thrifty gene” that once benefit human predecessors now works against them, causing their bodies to store more fat and leading to higher levels of obesity in the population.

Obesity is one consequence of mismatched genes. Known as “metabolic syndrome”, this condition is also associated with other health concerns, including insulin resistance, where the body no longer responds to insulin secretion, so blood glucose levels are unable to be lowered, which can lead to type 2 diabetes.