The 33-year-old actor said to Interview magazine Bagshawe encourages him to eat more.
"My wife saw some photos of me at the L A premiere, and she's like, 'Ed, you're looking underweight.'
"'I said, 'Baby, I've got loads of sushi and juices.' And she was like, 'That's not what I'm talking about! I'm talking a gigantic bowl of spaghetti Bolognese and a burger'," he said.
Redmayne married Bagshawe on December 15, last year.