Eli5: How do we know obesity is genetic and runs in the family? Is there something written in the DNA?



Probably a stupid question but I’ve always wondered this.

In: Biology

It’s not in our DNA as in, we have one gene that causes obesity (actually, there is one, but that’s a different story). But people can have differences in their metabolism (as in how many calories you burn while resting) and presumably also in how strongly they react to hunger or to food cues (commercials, smells etc).

Those differences are caused by an extremely complicated crosstalk between genetics, life style and even what your mother ate during pregnancy. So there truly is a genetic component, which means some people will just have a much harder time to remain at a healthy weight just because of how their body is ‘designed’, but it hardly ever is only this.

[8 Things About You That Increase Your Child’s Risk for Obesity and Unhealthy Eating Habits](https://www.huffpost.com/entry/diet-and-nutrition_b_4827359)

Parents tend to pass bad eating habits on to their children.

[Immigrants gain weight when they move to a country where the government subsidizes high fructose corn syrup. ](https://www.webmd.com/diet/news/20041214/for-immigrants-america-is-land-of-obesity#:~:text=Weight%20Gain%20Among%20Immigrants&text=Foreign-born%20adults%20were%20less,risk%20factor%20for%2)