How to lose the chef belly?

i'm an aspiring michelin star chef who works anywhere from 10 to 16 hour days 6 days a week. I am very conscious of what i eat during the day... i have nutella with a crescent roll for breakfast with a coffee, lunch is usually meat and rice and dinner is soup and meat scraps... i taste small spoonfuls of things over the course of the day but figured out i am only about 1650 calories. I exercise when i get home, walking for a half hour and some ab work but i wonder why am i not losing my chefs belly, its not that big (6'3" and 202 lbs) Does anybody have any tips that can help me??