(Yahoo!) - When did Nick Jonas grow up?

Kevin and Joe Jonas's younger brother flaunted his buff body on Instagram on Tuesday.

"I never do this but... Healthy living and fitness update. Post workout picture. #diabeticinshape #2.0," the hunky 20-year-old shared along with the above photo.

At the age of 13, Nick was diagnosed with Type 1 diabetes. Since then, he majorly cut back on his sugar intake and stays away from regular soda.

"When I wake up, the first thing I do is check my blood sugar, see where I am," Nick explained to Good Housekeeping in 2011 about what a typical day for him is like. "Then, I usually eat breakfast, typically an omelet because it has eggs, which are good, and other things that help me stay stable."

Nick, obviously, makes sure to get to the gym as well, although he admitted at the time it was hard to maintain a regular schedule while on tour.

Considering the Jonas Brothers are currently on tour promoting their upcoming album "V" — and judging by this ab-tastic photo — Nick must have somehow found the right balance.

Only question: Who took this sorta-selfie photo? It would be impossible to snap on your own from this angle … no?