Is there any evidence that weight gain is genetic? if so, what is it?

According to the article I've read in the website of Harvard Health Publishing (Harvard Medical School), the causes of overweight or obesity have been implicated by more than 400 different genes. Genes provide overweight in so many ways like metabolism, appetite, cravings, distribution of fats, and stress eating. Although it depends on one person to another person. Researchers have said that 25% of predisposition to be overweight is accounted to genes, while 70%-80% for genetic influences. These are just some of the reason how much of your weight depends on your genes:
-For much of your life, you have been overweight
-Overweight is seen on your parents or relatives, your likelihood to be developing obesity is as high as 80% if both of your parents are overweight 

They get pregnant at younger ages