What's your opinion on naturally thin people?

Everyone knows at least one person that is ALWAYS the same weight. It seems like no matter what they eat, or how much exercise they do (if any), they stay wafer thin year after year. While the rest of us starve our selves and exercise until the cows come home to be thin/“fit looking”....and heaven forbid you eat that piece of cake, because you WILL see it on your ass tomorrow.

ARE these people really naturally thin? Is it genetics? Or is there some secret? What’s your opinion? OR your secret…..