Jennifer Aniston stays slim by smiling.

The 'Wanderlust' actress - who is engaged to actor Justin Theroux - has learnt that dieting is no longer important to keep trim, and instead likes to spend time in the sun with a big grin on her face.

She said: "I stopped dieting when I figured out that you just have to ear regularly and properly within moderation.

"The fads are too much. I think it's really about - honestly, this is going to sound silly - going in the sun for 20 minutes a day is really important, vitamin D, because we are now having a vitamin D deficiency because of all the SPF. And I think being happy and smiling and laughing a lot."

All of the sun and smiling keeps Jennifer comfortable in her own skin, and she admits she is not terrified of doing nude scenes in films.

The 43-year-old actress told Britain's OK! magazine: "There's a little bit of nerves (with nude scenes). Adrenaline takes you through it. The girls come in and cover you up immediately. I got very comfortable with seeing nude people pretty much immediately. It was very bizarre."