Gary Barlow ''made big changes'' to get himself into better shape.
The Take That singer has opened up about how he focused on his fitness and managed to get himself down to 12 stone, five stone lower lighter than he was in 1999.
He told the Daily Mirror newspaper: ''I've made big changes. I take exercise more seriously now and I'm big on well-being.
''I eat well, do an acupuncture session a week and I try to sleep well and do things to aid good sleep.
''I don't eat sugar, I don't eat fried foods and I stay away from McDonald's and chips and things like that.''
The 'Let Me Go' hitmaker explained how he struggles to retain his weight loss and he has to be strict with what he eats.
He said: ''I've just not got the sort of body where I can pick and choose what I eat.
''I've got to go for one thing and sticky by. So I've tried not to have sugar and caffeine, etc, and it's boring, it's really boring. But it works for me. The result is that I feel good.''
Gary, 42, also puts himself through a strict exercise regime, choosing to regularly run and walk as often as he can.
He added: ''I do maybe four or five runs a week, perhaps every other day.
''I'll do a 6k on one of them and I'll do a sprint thing in the park on another day. Six or seven uphill sprints and I'm absolutely knackered by the end.
''I do high heart-rate stuff and try to be active in the morning. I'll walk Daisy to school in the morning and if I'm doing a phone interview I walk around at the same time.''
The novel's author saw a cut of the film and loved each of the changes the movie's director had made.