Colin Kaepernick, whose loss of weight and muscle tone was eye-popping this spring, has a solid plan for rebuilding his body.

“Eat food,” Kaepernick said, “and a lot of it.”

Kaepernick might be more seriously threatening to replace Blaine Gabbert as the starting quarterback for the 1-2 San Francisco 49ers if he looked a little more like the guy who led the team to the Super Bowl. Instead, three offseason surgeries took a toll, keeping him from the weight room and significantly diminishing his previous 225-pound playing weight.

“To get the full Kap for what you need — the potential that he has — he needs to continue to just work on the physical aspect of things,” 49ers Coach Chip Kelly said.

Kaepernick’s physicial condition was a shock at first, and there were questions whether the vegetarian diet he adopted nine months ago was partly to blame. It isn’t easy to maintain the kind of heft needed to play in the NFL without meat and dairy.

David Carter, a former 300-pound defensive lineman, broke down his diet for GQ last year, saying that he was trying to eat 1.2 pounds of protein from plants, beats, rice and grains every day during the offseason. Carter, whose tendinitis and fatigue lessened when he stopped eating meat and dairy, was consuming 10,000 calories a day over five meals (not including snacks).

So … when Kaepernick says he’s eating “a lot of it,” he means it.