While backpacking through Europe with my wife, I discovered an excellent strategy for not killing one another. Whenever she would get hungry and irritable, I’d retreat to a safe distance, perhaps behind a low hedge or cobblestone wall, and lob packets of chips in her general direction, only emerging when the munching sounds had ceased. I actually carried a small supply of travelling rations in our pack for this purpose.

Because, although my wife is smarter, funnier and more brilliant than me in every possible way, she suffers from the terrible affliction known as ‘hanger’ (a catchy portmanteau of ‘hunger’ and ‘anger’). When she doesn’t eat, she gets hangry. Symptoms may include grumpiness, irritability, a shorter-than-average fuse, and chasing your partner down the street with a baguette.

Scientists have been studying the link between hunger and mood for quite a while, and they’ve found some pretty concrete evidence that hanger is not only real, but also hardwired into the human condition. We were born to be hangry – and with good reason. It works like this: when we eat food, our bodies digest all the fats, carbohydrates and proteins and turn them into stuff the body needs to function, like simple glucose sugars, amino acids and fatty acids. Glucose is particularly important – it’s the stuff that keeps our brains working normally. Basically, it’s brain fuel.

When we don’t eat, our blood glucose level drops, and the brain naturally assumes this is a life-threatening situation – perhaps we’re being chased by something hairy with teeth – triggering all sorts of fight-or-flight physiological responses. Our pituitary gland starts pumping out growth hormones. The pancreas bustles off to make glucose-boosting glucagon. Our adrenal glands bulk-buy adrenaline and cortisol (aka the stress hormones). And neurons in the brain begin secreting neuropeptides – a type of neurotransmitter connected to things like anger, .

In other words: hanger is a survival mechanism sparked when your brain is hungry. Which makes sense, really. If our ravenous ancestors sat back politely while other cave people ate their grub instead of being maddened by their growling bellies, we as a species might not exist today.

Despite some crappy stereotypes, studies have confirmed that women are definitely not hangrier than men. If anything, there’s a slight neurological skew the other way (men have more receptors for those pesky neuropeptides). Personally, when I’m hungry, I just power down like an android, conserving precious energy by sulking quietly in the corner. According to my wife, that’s more annoying than irritability.

Across the many hanger-related experiments that have taken place, one thing is clear: the hungrier participants were, the more likely they were to experience a situation as stressful or unpleasant. (In the words of psychology and neuroscience professor Kristen Lindquist, “feeling hungry can turn up the dial on lots of negative emotions.”) One of the weirder trials occurred in 2014 at Florida State University, and was helpfully titled “Low Glucose Relates to Greater Aggression in Married Couples”. In it, folks were given a ‘voodoo doll’ representing their spouse, a sharp pin and the power to blast loud noises through headphones worn by their partner any time they felt angry with them. Scientists measured blood glucose levels throughout the experiment – presumably while giggling behind a one-way mirror. The results? Participants with lower glucose levels “stuck more pins into the voodoo doll and blasted their spouse with louder and longer noise blasts.” Matrimony is a complex and wonderful thing.

If you find yourself – or your spouse – suffering from hanger and you’re all out of pins, there are a few things you can do. Eating is the obvious answer, but try to avoid sugary junk foods. They’ll definitely spike your blood glucose level, but they’ll also send you rocketing down the other side, which probably explains why so many eighth birthday parties end in tears. The best things to eat are natural, nutrient-dense foods like grains, berries, cereals and nuts. Anything that can be quickly broken down into ATP – the brain’s favourite type of glucose.

If eating isn’t an option, perhaps because you’re stranded somewhere in western Europe, experts recommend tuning in to your emotions, listening to your body, and realising this isn’t your fault. You’re a wonderful, patient, rational human being. Your brain is just hankering for sugar. Now, for the love of god, eat an almond.

These tummy-rumbling insights comes straight from the pages of frankie 99. Head here to find your closest stockist, pick up a copy from our online store or subscribe from $59.50.