Megan Fox says cutting out dairy is the key to looking good.

The 'This Is 40' actress has bounced back to her stunning pre-pregnancy figure even though she only gave birth to her first child, Noah, in September and Megan credits lack of dairy with helping her to lose weight.

She told Hollyscoop: ''I'm not eating dairy, that's my biggest secret. It's really hard on your hormones and it's not good. If you want to gain weight, eat dairy. If you don't, don't eat it.''

It was recently revealed Megan only gained 23 pounds while expecting by keeping her exercise routine consistent.

The 26-year-old beauty's personal trainer Harley Pasternak said: ''We worked out throughout her entire pregnancy. She was a model of health through the whole process. She really educated herself big time and had a great relationship with her physician so she really understood the safe boundaries of how to exercise and eat well during pregnancy. As a result, she knew how active she could be and she was very consistent and didn't overdo it.

''As she progressed from trimester to trimester, we'd modify things. As a result, she was so fit at the point of delivery that it actually went more easily and she was able to get medical clearance relatively quickly to come back and keep working out.''