Carnie Wilson Keeps the Weight Off by Cooking

— -- Six years after her gastric bypass surgery, singer Carnie Wilson is keeping the weight off, but the desire to eat remains.

For Wilson, the supermarket is a minefield, especially the aisle packed with carbohydrates.

"I salivate. I flip out. Look at the sweet potato pie, strawberry rhubarb," Wilson told "20/20."

When you love food as much as she does, staying healthy is not easy. "I mean, moderation, not deprivation. That's my new way of living," said Wilson. "I always want more, and that's just my life."

Gastric bypass surgery successfully shrank Wilson's stomach, but it didn't reduce her passion for food. Now she's content to cook for others -- this poster child for gastric bypass surgery has written the cookbook, "To Serve With Love."

The book combines healthy dishes such as poached fish, with sinful items like macaroni and cheese. Click here for the recipe.

"You got the creamy filling inside. There's five cheeses in there," said Wilson. "I love to watch people eat."

It may be delicious, but a dietician told "20/20" the dish is 800 calories per portion. "Before, when I was 300 pounds, I would eat probably three or four times that amount," said Wilson.

Now, she only allows herself to have two bites of the dish at a time.

"One of the greatest pleasures in life is eating. … We need to eat and enjoy it but control it," said Wilson. "That's what I do now."

Wilson's healthy approach to eating is a long way from where she was in 1999, when she had her gastric bypass surgery.

At age 31, Wilson was morbidly obese, like 6 million other Americans are today.

She spoke with "20/20" at that time and described how she felt at that weight. "My feet were hurting; I would be tired a lot, I'd feel sluggish. I started getting paranoid … I felt like I was going to have a heart attack," said Wilson.

She was dubbed the "fat one" in the hit singing trio Wilson Phillips and her weight trouble started early on. She says she picked up erratic eating habits from her famously troubled father, Brian Wilson of the '60s pop sensation The Beach Boys.