Here are the top diet and fitness tips the stunning brunette swears by.
"I like having a good protein meal because I get really tired if I eat too much,” says Bella.
“I order a lot of green juices and keep them around on set. I have ginger shots in a cooler and I'll drink one if I'm feeling low.”
Post workout, “I eat something full of protein like chicken and wholegrain rice,” says Hadid.
“It's ideal to strengthen the muscle mass and to increase the effects of the session."
During training sessions, “I run non-stop for 20 minutes followed by a boxing session and finally a series of weights targeting the abs and glutes,” says Hadid. “We keep the routines varied, so the sessions are always fun."
"A secret to success is “to put in 100 per cent from the start to the end of a workout,” says Hadid.
"Going to the gym for two hours with only 50 per cent motivation erases any feeling of accomplishment.”
Read more on celeb body tips in this week's issue of WHO, on sale now.