(NBC News) – Scientists looked at the genes of millions of people to determine which ones are linked to obesity — and developed a way to screen people before age 5.

Certain genetic variants can affect how a person’s body stores fat or make them more prone to overeating. Genetic variation can also predict how well a person will respond to different weight loss drugs.

In a study published Monday in the journal Nature Medicine, more than 600 researchers from around the world worked together to compile genetic data from more than 5 million people — the largest and most diverse genetic dataset to date. They also used genetic data from 23andMe. (Read More)