Do skinny people have “skinny genes” and fat people have “fat genes”?

Written by Nyomi Graef

​There is a belief that it doesn’t really matter what we eat and drink. If our families are fat then we will also be fat because we have the “fat genes”. Skinny people have the “skinny genes”. Is this true? Yes, some people have a genetic condition that makes them put on weight. But this is only a small amount of people. Also some illnesses and medications can make people gain weight. But this only explains why – or part of the reason why – some people gain weight.
 
Families often share the same eating and exercise habits. It’s common for parents to pass on their lifestyle habits to their children. Families who do little exercise and eat lots of junk food, white flour and/or added sugar (but low amounts of healthy unprocessed and minimally processed foods) are very likely to be overweight and obese. The bad eating and exercise habits of these families is (or is most likely) causing them to be overweight, not their genes.
 
Our eating habits affect our genes, organs, mood and so on. For example, if people eat a very unhealthy diet for years, then develop a thyroid problem caused – at least in part – by their eating habits, is blaming their genetics (“Mum/Dad also had a thyroid problem, so I have one”) realistic? If the people ate a very healthy diet, exercised regularly and had other healthy lifestyle habits, would they develop the thyroid problem? Even if people have a genetic predisposition to a disease, various factors affect whether or not they develop that disease. Their environment, eating habits, emotions, hormones and more all affect how genes are expressed.
 
Overweight and obesity rates have been increasing in many countries for only the last few decades. The World Health Organization says that: “Worldwide obesity has nearly tripled since 1975.”
 
Our genes have not changed that much during this time to cause such high rates. Our eating and exercise habits have changed immensely.
 
Key reasons for weight gain include:

• a high intake of added sugar, white flour, white rice and/or junk foods. The number of fast food outlets, unhealthy pre-prepared meals etc. has skyrocketed in the last few decades.
• comfort (emotional) eating foods high in salt/fat/sugar because of stress, depression and/or loneliness. Over time, eating lots of these foods can cause changes in people's biochemistry, leading to becoming addicted to these foods. Interested in knowing more about food addiction? Read obesity expert Dr Robert Lustig's views and resources on this topic on his website.
• a low intake of fruit, veggies and dietary fibre. Most Australians (among other nationalities) don’t eat enough fruit, veggies and fibre needed for good health.
• poor access to healthy foods, and easy access to unhealthy foods.
• a lack of physical activity. The increase in number of sit down jobs, cars, lifts, escalators and more all contribute.

 
So conquer comfort eating, get enough exercise, and have healthy eating, thinking and other lifestyle habits. They will steer you onto the road of good health, increased happiness and easier weight loss.