Ever envy people who can fill up their tray, eat everything on it and never get fat? Maybe you are one of the people who feel you are too skinny and have tried to gain weight — but couldn’t.

Stop fretting. Weight gain is a combination of genetics, daily activity and other factors.

You’re at the diner and a group of four, slender people get in the booth behind you. You’re sipping coffee and eating your egg-white omelette as they order: “Buffalo-chicken wrap and fries, bacon cheeseburger — deluxe, macaroni and cheese, and the chipped beef special.”

You begin to enviously wonder: “How are these people staying so thin?”

The answer is obvious and complex. Information shows genetics is the greatest determination of weight gain and influences about 60% of the variation in a person’s susceptibility to obesity.

Blanca Herrera, a doctor of human/medical genetics, says, “Genetics influences metabolic rate which permits some to naturally burn calories faster than others.”

Reasons Beyond Genetics

There are reasons beyond genetics which contribute to weight gain— or the inability to put on weight. Skinny people may be less sensitive to routine food clues such as the sight of pizza or the smell of fried food.

Then there is daily activity. Everyday routines, such as climbing the stairs instead of taking the elevator may seem insignificant, but over time a lot of calories may be burned.