The secret to staying fit may be in your head

(NBC) - Your personality may determine whether or not you become obese.

Sandra Stern just dropped six dress sizes, and she's still losing. She says she packed on the pounds in nursing school.

"They talk about the freshman 10, 15. Well mine was more like the freshman 30," Sandra said.

She says work was stressful, then she had two girls. Over time, it piled on.

"It's that nurturing. It's the reason that I do what I do as a nurse, having children. It's a natural thing to want to nurture your children," Sandra said.

The psychological side of overeating is so critical, U-T Southwestern Medical Center now dedicates a health psychologist solely to its bariatric program. Dr. Martin Deschner says there's a definite "prototype."

"Someone who gives a lot to others, someone who is a caretaker," Dr. Deschner said.

Deschner says stress is usually the trigger, and this personality internalizes stress.

"They are peacemakers, you can think of it like that. They don't like to be argumentative very often. Handling situations assertively is often not their strong suit. These people are giving every which way, but they are not taking care of themselves and the only way that they can find to do that many times is to eat," Deschner said.

Deschner also says many people are depressed and don't realize it. A study reported in The Archives of General Psychiatry, found depression increases the risk of obesity by 58 percent.

Sandra, four months after bariatric surgery, is working on the mental side of keeping it off. Her family now eats healthy and she's letting her girls carry some of the weight in the kitchen.

"I also realized that I wasn't giving my kids a gift by showing them that being a nurturer and giving everything you have and not giving anything back to yourself is not a gift for them."

Dr. Deschner tells patients to take 30 minutes out of each day to completely relax, thus, managing their stress.

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