07/31 — Today is Rex Ryan’s first day as an NFL head coach at training camp, and one thing on his mind — besides the Green & White — is no doubt his next solid food.

Ryan announced at the top of today’s news conference that today is also his first day on a diet.

“We’ll see how long that goes,” Rex told reporters. “You guys may want to have a bet with each other. It’s all liquid or something like that for five days. It’s going to work great. I feel good. I had oranges, lemons and all that stuff to squeeze in there. It was a great breakfast. I’m looking forward to the vegetable thing that they have for me today.”

The Jets coach said he topped out at 340 pounds and now he’s going back in “the other direction.” His target weight.

“I think around 300. ... OK, 310. I kind of figured you weren’t buying that one.”

If Ryan needs any inspiration, he doesn’t have to look farther than defensive tackle Howard Green, another player from the school of big men who has slimmed down this off-season.

“Howard Green, running with the second defense, showed what he’s all about in those 9-on-7 drills and those inside drills. That’s why he’s here. He is a big, physical presence. He used to be ‘Big Howard.’ He’s not so big anymore. I think he dropped 20 pounds or something like that, and I don’t think it’s fair to say it was like losing a deck chair on the Titanic, either. I might have put on the weight that he lost, unfortunately.”

Another motivational ploy may also be to involve Jets fans in a new charity.

“You could ask [Marques] Douglas and some of these older guys that have been with me,” he said. “Every year I used to get the weight up a little bit and then my kid would play on a travel baseball team. So to raise money, I would have to lose 30 pounds. So this is not new for me.”