The 42-year-old 'Departed' star, who had bulked up for his role in 'Transformers: Age of Extinction', said he wanted to slim down again after for his next role, reported CNN online.
"I began with a liquid diet. Then I completely changed my training programme and gave up wine, bread and pasta. Now I'm eating small portions of protein throughout the day and jumping rope a lot. Everyone is trying to get me to stay thin now," Wahlberg said.
"I'm just disciplined. I have an appreciation for the fact that I'm in a unique situation to be able to do all the things I want to do. I don't take it for granted, and I don't know how long it will last, so I've got to be on my A game. Today we had a 4:40am call time, so I got up at 1am," he said.