As much as Amar’e Stoudemire credits Hakeem Olajuwon for teaching him post moves this summer, the Knicks forward is gaga over his vegan diet and believes it is the key to his bang-up return from knee surgery. Stoudemire recently went off the vegan diet for over a week, but his play didn’t suffer. He didn’t take any chances, though, and he returned to veganism yesterday before scoring 19 points in the Knicks’ 106-96 loss to the Wizards in Washington. “I just needed a break,’’ Stoudemire admitted. Stoudemire said a mixture of asparagus, brussels sprouts and salads have worked wonders. Last night after the loss, he sat with a plate of spinach and broccoli as his teammates downed postgame pasta and sausage. “It purifies the red blood cells and eliminates toxins,’’ Stoudemire said. “It fortifies the blood. It helped me recover and persevere through injuries. I did that for three months. I wanted to really give myself the best opportunity to remain healthy.’’ It wasn’t easy and Stoudemire needed to take a little time off to dine on his favorite foods. “It was tough,’’ Stoudemire said. “I love chicken and I love Chilean seabass. I missed it. But I wanted to stay strong.’’ Stoudemire believes his vegan plan inspired Carmelo Anthony to go into his January fast and triggered Mike Woodson’s recent diet. “It’s just rewarding to be healthy,’’ Stoudemire said.