A friend of mine has been vegetarian for years. She very much believes in not eating animals. Until she's drunk.
We all know someone who ends up eating a bag of pork scratchings or a McDonald's beef burger after a night on the tequila.
Veggies eating meat
In fact, a survey found that a third of vegetarians eat meat when they're drunk, with 69 percent of those doing it keeping it a secret from friends and family.
Of those who ate animals when drunk, 39 percent said they ate kebab meat, 34 percent opted for beef burgers, and 27 percent admitted to eating bacon.
But why does this happen?
Eating animals when drunk
A while ago, the University of Liverpool looked into why we crave fast food when we've been drinking, looking at the effects alcohol has on energy intake and dietary restraint.
They found that after 50 undergraduates had had some vodka lemonade, they eat more cookies than those who were given a placebo drink - which they put down to impaired inhibitory control.
In other words, being inebriated stops us from being able to say no.
Craving junk food
Many people believe there are two reasons why we crave junk food. One is that it tends to be salty and full of 'orosensations' - crunchy chips, crispy bacon. Others say the craving is the result of the body crying out for certain macronutrients.
That heady blend of fat, sugar, and proteins is irresistible to our brains. And because of that mix, we think that we're getting nutrition - though we never really get full from it.
It's kind of the same as when we're hungover.
Alcohol and cravings
According to Because Science, another factor is our production of something called galanin. Galanin is a neuropeptide - a very small protein that resides mainly in the nervous system, including the brain and spinal cord.
In laboratory rats, injection of galanin into a specific area of the brain, called the paraventricular nucleus, increased food intake in the hour after injection. When scientists created mice without the ability to produce galanin, they found that they ate less fat.
When you drink, alcohol increases the amount of galanin in our brains, and scientists found that when they injected rats with galanin, they voluntarily drank more ethanol.
So, eating fatty foods and consuming alcohol both cause your body to produce more galanin, which in turn drives you to eat more fat and drink more alcohol. In other words, it's a vicious cycle.
Triggered by memories
Another theory is that once you've once eaten something genuinely delicious, your brain registers and remembers that feeling. That means that every time you see or smell that food, your brain starts triggering the memory and responses you had when you ate it last.
So, if you used to eat crap on your night out before going plant-based, you’re fighting a battle with your subconscious every time you walk past a kebab shop at 2am.
Not only does your brain know that it'll get a hit of protein, fats, and glucose - a macro balance which is thrown out of kilter when you've drunk a load of alcohol - but it also remembers just how good it used to taste - whether you want to remember or not.
Late night vegan
The problem probably is that there aren't enough plant-based junk food outlets open late enough to cater for drunk veggies who then find themselves in McDonald's confronted by loads of previously-desired options.
So come on vegan entrepreneurs, let's get some late night licenses rolling.
Who wouldn't want to be stumbling into What The Pitta or Vurger Co at 2am?