I honestly don't think he's kidding
Prior to the reveal of Tom Clancy's The Division at E3, Ubisoft shot a behind-the-scenes video with Massive to document everyone's emotions in the days leading up to the announcement of the game. There's a lot of normal "we hope everything goes off without a hitch" banter until Nicklas Cederstrom, the creative director, explains that he ate leaves and flowers to prepare to make The Division.
Apparently, in an attempt to understand what's it's like to need to survive without everyday luxuries, the team went out into the wilderness and roughed it for a few days. "I would never do it again. Leaves taste really bad when you boil them, but you have to survive," Cederstrom said.
Hopefully, this all leads to the creation of a better game, but I'm having a tough time directly correlating the two. I'm going to go out on a limb and venture that you unnecessarily ate leaves, dude.