What happens when people go out drinking? I mean, other than the obvious.

Turns out, they tend to abandon their vegetarian food preferences long before last call.

Here is a classic piece of market research.

It originated in Great Britain, but even a cursory review of the data would lead most people to conclude that similar results would be highly likely to be replicated on this side of the pond.

According to a survey reported on the website VoucherCodesPro.com.uk, which appears to be one of those coupon vendors offering consumer discounts to various retailers, many people who claim that they are dedicated vegetarians seem to lose their dietary devotion after they’ve quaffed a pint or two at the local pub.

The survey involved 1,789 self-professed U.K. vegetarians and asked respondents the following question: “When drunk, do you ever eat meat?”

In response, more than one-third of those taking the survey (37%) admitted they did eat meat when drinking, while the other 63% insisted that they never ate meat, even when drunk.

Such a significant defection — more than one of every three people — undermines the assertion veggie activists always make about how pure, noble and religiously dedicated they are.

But here’s what’s even more interesting from the survey results.

According to the website post, respondents were instructed to choose how often they “indulged” in meat-eating when drinking. The results were revealing:

·         Every time you get drunk:          34%

·         Fairly often:                              26%

·         Rarely:                                      22%

·         Occasionally:                            18%

That means that more than half of so-called vegetarians are wolfing down sausages, fried chicken or bacon burgers pretty much every time they spend an evening in a pub. And those results were from a voluntary survey in which nobody was under pressure to admit any “guilt” over falling off the veggie wagon.

People could have shaded the truth, and no one would have known.

Here’s the bottom line to the survey data: In response to a final question, some 69% of the meat-eating vegetarians (there’s an oxymoron for you) admitted that they didn’t tell anyone else about their meat-eating activities.

Meatless no mo’

That says two things: One, vegetarians tend to be extremely judgmental about other people’s dietary preferences. If you hang out with avowed veggies, it’s not a smart idea to admit that you wolf down meat of any kind on any occasion, intoxicated or not. Try it, and you’ll be severely chastised, if not totally ostracized.

Second, humans have a built-in appetite for animal foods, and all it takes is for those judgment centers in the cerebral cortex to go on a little alcohol-induced slowdown, and we start craving the very foods that veggie activists claim are so harmful to human health.

There’s a reason for that, and it’s straightforward and factual. Meat and milk are the foods that fueled the eons-long development of human physiology — including those big ol’ frontal lobes we possess where all the rationalization about plant-based diets is stored — and our biological systems are precisely adapted to thrive on the nutrition they provide.

That’s why people give in to their cravings for meat after a couple of drinks, and that’s also why a 2014 survey by the Humane Research Council of Olympia, Washington, discovered 84% of newly minted vegans and vegetarians abandoned their meatless diets in less than a year.

Even some high-profile vegans, such as New York Times columnist Mark Bittman, admit they “occasionally” eat meat. How occasionally that really is in Bittman’s case, however, isn’t subject to a similar level of transparency.

The innate desire to consume animal foods arises from millennia of interaction between humans and their various lifestyles, habitats and cultural traditions — virtually all of which, with the exception of some monks and aesthetics, incorporated both game meats and animal foods from domesticated livestock into their daily diets.

Truth is, we shouldn’t have to suck down enough booze to shut down our higher-level reasoning before we allow ourselves to choose the foods that are natural and necessary for optimal health.

And we definitely shouldn’t be keeping it a secret.

Dan Murphy is a food-industry journalist and commentator.