The NCIS star took the summer off his top-rated drama to shed a whopping 35 lbs. from his 6' 2" frame. The actor told PEOPLE that he got so heavy that he "split five pairs of pants" during season 11.
"Here's the skinny," joked Weatherly, 46, who plays Anthony DiNozzo on the CBS series.
"I have two very small children, ages 2½ and 1 year old. That means I had been living with a pregnant lady for a long time. While my wife [Bojana Jankovic] never gave in too much to her Nutella craving, we weren't doing too much. And I found it very hard to say to my wife and children [Olivia and Liam] that I need to spend a couple of hours on me. And the job was demanding."
"This is not an excuse, but the craft-service table is not filled with a lot of super healthy options," continued Weatherly. "Then you get to working late, there's pizza and Chinese food. You try to be good. But while the crew guys are lifting things and pushing things, I just tended to sit at the trough and continue to graze. That's my long-winded way of saying things did get away from me. It reached a tipping point. Even the writers made jokes about Tony needing to go on a cleanse."
At the end of season 11, the actor turned to trainer Juliet Kaska, who encouraged him to cross-train with sports like boxing and swimming in the ocean. "I do it every weekend," he says. "I love it. You become very alive when you are in the ocean."
As for his diet, Weatherly pretty much gave up most carbs. "No food that comes from a package like potato chips," he said. "I stayed away from pasta, rice, bread, potatoes … anything that's fun to eat, I did not eat. And I pulled way back on alcohol consumption."
His hard work paid off: Weatherly went from 240 lbs. to "around the 200-lb. marker." He even participated in his first triathlon (that's him at the finish line, above) in Malibu on Sept. 14.
"I was really gratified when I went into wardrobe at the start of the season and could fit in a season 1 jacket. That was 12 years ago!" said Weatherly. "Most importantly, I had more energy and more stamina. It's very hard. I go through periods of working so hard, I don't know when to exercise. And I'm surrounded by some food options that wouldn't be my first choice. But you do the best you can."
"I discovered great things about myself at this stage in life," he added. "You have to take time for yourself, whether it's reading a book or going for a walk or just spending some time talking to a cat. At a certain age, you have to take care of yourself. No one is going to do it for you."