Jennifer Garner speed dials her nutritionist at night so she doesn't break her diet plan.

Nutritionist to the stars Kelly LeVeque counts Jennifer as one of her clients and she has spilled that the '13 going on 30' actress sometimes calls her late at night when filming to get advice on how to avoid late night cravings.

Speaking to Us Weekly, Kelly said: ''She'll text me, she'll call me, 'Hey, I'm on HBO's Camping. I'm filming like every single night from 11pm to 3am. What can I do?'

''I might pull back on the alcohol. I might say, 'I know you love your red wine but let's not have that'. I also might add a little more protein so she feels more full because that lack of sleep is gonna increase her hunger hormones. So it's really just ways to prevent her craving, crashing and sort of feeling bad about yourself.''

The 46-year-old actress is currently working on her new comedy series 'Camping' from Lena Dunham and Jenni Konner - which tells the story of a married couple who go on a trip that goes horribly wrong.

Kelly - whose other clients include Emmy Rossum, Chelsea Handler, Busy Philipps and Jessica Alba, among others - believes the best advice she has been giving Jennifer, 46, is to eat high quality foods packed with vitamins and nutrients.

She said: ''With Jen, it was really about being sure she was getting that quality down - making sure she was cooking with healthy oils and getting really healthy proteins. She has a garden and prioritises getting healthy food and understands the process of regenerative farming, which is basically having your produce and your chickens all in the same area. It's really good for the soil, it's really good for the land and it's really good for the health of the actual plants that you eat.''