The British rocker Morrissey got Madison Square Garden to ban meat and fish for the night of his June 27 concert, as The Post exclusively reported last week.

When a musician who once declared, “There is no difference between eating animals and pedophilia” can cow the Mighty Dolans, MSG’s owners, to his whim, something creepy’s going on.

Gag on it, dude — you and all your fellow travelers in nutritional sanctimony.

Morrissey belongs to the vegan lunatic fringe. But although he’s more obnoxious than most culinarily correct proselytizers and propagandists, his righteousness differs only in degree from the hypocrisy and baloney that bleed through the politicized dining scene.

As a restaurant critic who’s a Type 2 diabetic, I take nutrition as seriously as taste. My blood sugar was once so high, doctors believed I needed massive insulin injections.

Although I got it under control with oral medication and, later, diet alone, I know well the dangers of glucose, over-processed junk food, over-consumption of fat, empty calories and all the myriad failings of the American way of eating.

Yet the absurd claims being made for all kinds of allegedly healthful and/or environmentally virtuous regimens make me want to wretch.

Sorry, vegetarians and vegans: I love meat and fish and products derived from them. So do most human beings. Depletion of the oceans and of certain land species is a serious issue, but I’m interested in sustaining my appetite, too.

Few respectable chefs take seriously the rantings of “Food Babe” Vani Hari, who finds “toxic” ingredients in everything. (A must read is gently titled “The Food Babe Blogger Is Full of S–t” by quackery-debunking analytical chemist Yvette d’Entremont, a k a “Science Babe.”)

Yet only slightly less looney views hold sway everywhere. Restaurants all over town now push gluten-free dishes such as all the desserts at popular new Italian spot Santina. Gluten, a naturally occurring protein, is a danger mainly to victims of celiac disease, which afflicts 1 in 133 people, according to the University of Chicago.

Not surprisingly, critics agree that Santina’s desserts are the menu’s weak link. Yet the kitchen, indulging the fad scourge of the moment, regards gluten as a graver risk to sensitive systems than scorching chilies, rich sauces and nuclear-strength cocktails that could fell a charging buffalo.

Waiters around town routinely assure us that water is triple-filtered in-house, as if ordinary tap or bottled H2O were a writhing bacterial sea.

Claims that chickens, pigs and cattle are “humanely” raised might grate less if restaurants showed more humanity to employees who are cheated out of tips and sexually harassed.

Chef Dan Barber, an influential and articulate proponent of enlightened agricultural methods, recently turned his Blue Hill into a pop-up called “WastED.” For several weeks the menu consisted entirely of dishes made from discarded food remnants.

The elitist notion was to educate us on not only how much Americans throw away, but that stale, damaged and otherwise tainted elements can be made delicious.

Some dishes, like “cured cuts of waste-fed pigs,” indeed tasted swell. But they were hardly just tossed together from scraps.

As The New York Times’ Pete Wells discovered, they were laboriously contrived from a “crosstown refuse hunt” to unearth very specific items from the Battery to The Bronx — an endeavor certain to be embraced by home cooks with unlimited time on their hands.

It’s a perversely delicious irony that all the anti-meat, anti-gluten, anti-preservatives, anti-lactose, anti-genetically-modified, anti-anything-edible campaigns have not made a dent in the way most Americans eat.

We’re just as beef-addicted, and fat, as ever. And while I deplore this as much as anyone, I recoil more from the meal I had at Farmer’s Table, a Florida restaurant much celebrated by the “sustainable” crowd.

Its menu touted a “lifestyle of wellness,” “commitment to fresh, honest food,” “exceptionally clean ingredients” from “eco-conscious purveyors,” no “excess fat, sodium or preservatives,” “no cream or butter” and shrimp from Belize that “swim in filtered sea water, [are] fed a vegetarian diet and not treated with additives or sulfites.”

That wouldn’t be enough to make Morrissey happy.

But I wasn’t happy either with dishes that were moisture-deprived and flavor-free — what usually happens when politics is stirring the pot.