The 36-year-old actress said she keeps her body in top condition by following an alkaline diet, which focuses on balancing pH levels and acidity, reported Contactmusic.
"I live by a rule book of eating alkaline - no meat, no dairy, no gluten (and) I try to stay away from sugar - but I'll cheat when I want to, since I'm a bit of a foodie," she said.
"I try not to make it not so much about dieting, but rather everything in moderation."
Hudson, who is a co-founder of activewear brand Fabletics, sticks to a regular fitness routine, but when a major red carpet event is on her schedule, she steps her exercise up a notch.