Thrifty gene hypothesis – What is it?

Over the last century, there has been a significant rise in obesity. People all over the world have been affected by it, but it is seen that the western world has experienced it more. James Neel, a geneticist, proposed the thrifty gene hypothesis to resolve an elementary problem. According to him people are fat because of their genetic predisposition. Obesity, a global epidemic,affects almost 300 million people all over the world. Unless the fundamentals are not tackled, we will be unable to understand the disease in depth.

Inheriting obesity

A research shows that people from Polynesia, South-east Asia and Africa have greater susceptibility to obesity. This is because there is more probability that they have inherited genes that encourage storage of fat. There is sufficient evidence to prove that in societies where high-fat food is available with ease and at less cost, people have more chances of becoming overweight. One might also think about the reasons why people remain thin, in spite of the easy availability of calories. The answer is our genes, and the way they interrelate with environmental factors. The “heritability” of being overweight is equal to that of height.

Thrifty gene hypothesis explained

People of certain ethnicities, such as Pima Indians and Polynesian islanders, are more likely to become overweight, when they adopt western diet and lifestyle. Obesity affects one third of America’s population, and it is seen that African-Americans have an increased rate of obesity, than Americans and Europeans. A difference in rates of obesity was observed amongst people from different ethnic groups. This can be attributed to their genetic histories. People, who have lived in poverty, have little access to regular and high caloric food. The body starts storing energy for times when food would not be available, so that it can survive. Fatter people would survive easily during times when food was scarce. This is known as the thrifty gene hypothesis. However, in modern times, food is abundant and people get prepared for a famine that never comes.

You can fight your genes

People, who have descended from the inhabitants of the Western societies, experienced a reduced risk of starvation. Humans today carry genes of both these environments. If this is taken to be true, it can be said that the root of the problem is the interrelation of our genes with the environment. Lean people carry genes that protect them from obesity, while those who are overweight carry genes that are traits of our ancestors, who went though nutritional privation. A separate study shows that obesity is in our genes, but a minor alteration in our lifestyles can protect us from obesity. An overweight individual can lose 2lbs. every year by walking an extra mile everyday. This can be achieved by a proper diet as well. When we look at the whole picture, than just parts of the whole, it is obvious that the interaction of the environment with our genes causes obesity. We need to understand the problem in detail. Changes in food intake and exercise will help us overcome it. Obesity treatment is available for people who want to get back in shape.