What's in Jennifer Aniston diet that makes the 45-year-old "Friends" actress still desirable at her age? There's no denying that Jennifer Aniston has the body that almost everyone envy of. Why not? At 45, she has a natural toned slimmed figure that makes her the "sexiest woman alive in 2011."

Many are wondering what's in Jennifer Aniston diet that she managed to stay fit and young. Jennifer Aniston's yoga trainer Mandy Ingber spoke to ABC News and revealed that the slim actress knows how to cut down on snacking especially when she needs to.

"Jen's a very consistent exerciser and eater," Ingber stated. "But when she has something she needs to focus a little more on, she just tightens it up a little bit. It's kind of like just being disciplined, she's like anyone else that she goes through those times when she can lose a little but pretty much, she's always in great shape."

According to The Jennifer Aniston Diet, the "Friends" actress follows "Zone Diet" that is developed by Barry Sears. Zone diet is mainly composed of 40 percent carbohydrates, 30 percent fat and 30 percent protein everyday.

 Jennifer Aniston diet focuses on carbohydrates coming from fruits and vegetables, protein from chicken, turkey, tofu, fish and beef while fats are coming from olive oil, avocadoes and fish oil.

Are you curious about the meals that Jennifer Aniston is eating? Here's a sample of Jennifer Aniston Diet plan:

Jennifer Aniston Diet Plan:

Breakfast: Whole wheat toasted bread with Apple butter, cheese and cereal bar or Ginger peach shake with coconut water

Lunch: celery soup, salad with white beans, parsley, tomatoes, green onions and chives or salad with cheese, tomatoes, cucumbers and lentils.

Dinner: Chicken burrito without cheese or sour cream

Sometimes, Jennifer Aniston diet also includes high-protein, low-fat which she incorporates with omega-3-rich fish oil that helps her enhance her hair and skin, control weight and improve her heart health.  She also adds water is very important to flash out the fat cells.

Jennifer Aniston's personal chefs are Jewels and Jill Elmore who believe in these practices:

Balance is the key to achieving ideal weight. Starvation is a no-no.

Experiment on varieties of fruits and vegetables. Eat different fruits and vegetables or combined them.

Make each meal made of 75 percent vegetables along with healthy grain and little protein.

Aside from Jennifer Aniston diet regimen, the beautiful slim actress combine diet, exercise and yoga to keep her bod trim. The "friends" actress makes it a point to workout at least five to six times a week and always end the day with sit-up's and stretches.

Aside from Jennifer Aniston diet, exercise, and yoga her trainer Ingber added Jennifer's positive outlook in life is what makes her really glow and look young at 45.