Eating regular meals can help in terms of making better decisions and choices. — EKRULILA/Pexels
In 1765, widespread protests over bread shortages sparked riots in Paris, foreshadowing the French Revolution. Centuries later, researchers uncovered a hidden thread in many such upheavals: hunger. While revolutions are complex situations, studies now suggest that empty stomachs were a primary driver in many such events. And the state of our stomachs also shape our everyday choices, from workplace conflicts to unhealthy shopping habits.
The term ‘hangry’, a merging of the words ‘hungry’ and ‘angry’, may sound frivolous, but its implications are profound. Neuroscientists argue that hunger does not merely nudge behaviour – it hijacks it. Today’s column explores how an ancient biological drive surreptitiously dictates modern life, challenging our notions of free will, morality, and even love.
Biology of hunger
Hunger is not just audible pangs from a growling stomach. It is the fundamental consequence of a sophisticated biological chain of events involving hormones, our brains, and survival mechanisms embedded in our cells.
Produced in the stomach, the hormone ‘ghrelin’ is the body’s hunger alarm. A 2013 study found that rising ghrelin levels correlated highly with impulsive decisions. When ghrelin spikes, the brain prioritises food-seeking over logic – the hormone acts like a survival override button.
Another hormone called ‘leptin’ is produced by fat cells, and acts as a satiety signal. But overweight/obese individuals often develop resistance to leptin, which blunts this signal. Particularly affected are people with metabolic syndrome, a condition which affects potentially around 1.4 billion people on Earth.
Being hungry can make you 60% more likely to purchase non-essential non-food items, according to a 2015 study. — ENERGEPIC/Pexels
A 2012 study found that leptin injections reduced food intake by 17% in normal people, yet the hormone’s effectiveness is much reduced in overweight/obese people. This shows that leptin is not a magic switch which turns off eating. The experience of hunger is therefore a function of a biological dialogue between our hormones and metabolic health, and the discussion does not always go as planned.
Low blood sugar does not just cause dizziness – it impairs judgment significantly. A 2007 study found glucose-deprived undergraduates struggled with self-control tasks. This is not surprising as the brain burns 20% of our energy, a huge proportion relative to its size. Without adequate glucose, the study confirmed that willpower and judgement are negatively affected as the brain runs low on fuel.
A pea-sized portion of the brain called the hypothalamus literally lights up on fMRI scans when people are hungry. Other studies found a 38% spike in hypothalamic activity when participants viewed food images. This indicates that the desire for food is a primal need, and therefore alleviating hunger is not a conscious choice – it is a hard-wired biological mandate.
Hunger and decision-making
From the above, it is evident that hunger does not only make people crave snacks, though it does that pretty well too. More than that, hunger rewires what we think of as “conscious” decisions and/or free will.
In a 2014 study on gambling, fasting participants took 22% more risks. Hunger pushed people to take more risks which they would not undertake if they were not hungry. Evolutionarily, it may seem that hunger had pushed hunters into taking more risks for food. Today, it might explain why US President Donald Trump insulted Ukrainian President Volodymyr Zelensky in the Oval Office in a meeting which took place before lunch.
Another study revealed hungry people are significantly more likely to make selfish choices, over 30% of the time depending on the experiments used. It appears that hunger forces the brain to focus its limited cognitive resources on managing food scarcity, and this necessarily narrows the scope for empathy towards others. It is simply harder to be a saint when one is starving.
A study found that people with lower glucose levels showed more aggression towards their spouses. — PIXABAY/Pexels
Research in Shanghai in 2017 suggested that persistent food scarcity is correlated with poorer economic outcomes for affected people. This may be because chronic food insufficiency created a mindset focused on scarcity management rather than ambitious achievements. Curiously, the same study found that women handled food scarcity better than men, or at least were less impaired than men when faced with extended periods of hunger.
An odd 2014 US study tracked the link between aggressive behaviour and glucose levels of 107 couples over 21 days. Aggression was monitored by curious metrics such as the number of pins stuck into voodoo dolls of their spouses and the intensity of noise blasted against partners. Unsurprisingly, those with lower glucose levels showed notably more aggression toward their spouses. This indicates that glucose does not provide only energy – glucose clearly also affects emotional regulation. In short, try to never argue on an empty stomach.
Not just food
In an unusual twist, a 2015 study with US and Hong Kong collaborators found that hungry people spent over 60% more on non-food items in shops than people who were not hungry. This was unintuitive because stuff such as stationery or TVs would never be able to alleviate hunger. So what explains this behaviour?
The theory is that hunger amplifies ALL urges, not just for food items. So when a hungry person gets the ghrelin hormonal message “I want food”, somehow this gets translated by the brain to simply, “I want”. And “I want” can apply to just about anything else, including non-food items. Basically, an inner desperation for food gets translated into an inner desperation for other items.
This behaviour may have stemmed from Palaeolithic times, when hunters on failed hunting trips may acquire on the way home non-food items which may be later turned into other useful implements, as a form of “second prize” for an unsuccessful hunt.
Hunger’s far-reaching clutches
As primary sources of food, grocery shops and supermarkets are well-designed to exploit human hunger. The placement of many items is deliberate and designed to capture the “I want” impulses of customers, many of whom would remain hungry until they can get home to cook.
A 2014 study showed that hungry people take more risks compared to people who have eaten well. — STREETWINDY/Pexels
Beyond individual concerns, recognising hunger’s profound effects have broader, serious social significance. With chronic food insecurity currently affecting over 800 million people globally, such a scale of persistent hunger is shaping life outcomes, community dynamics, migration patterns, and even geopolitical stability. For example, food insecurity, especially in urban settings, correlates strongly with higher crime rates and social/political instability.
Free will vs determinism
Philosophers have been debating free will for thousands of years. The subject of hunger adds a confounding biological twist. Far from idealistic individualism and free will, it is not implausible that people are mostly behaving like robots desperately afraid of hunger.
Ancient Greeks called such behaviour “akrasia” – acting against one’s better judgment. Hunger-induced impulsivity fits neatly into this framework. We know we should not splurge needlessly or be unkind, but too often hunger can hijack our best intentions to be thrifty or kind. In that way, determinism may be a plausible argument as it may sometimes be impossible that a person could have made any other decision or performed any other action when pressured by hunger.
If hormones and glucose dictate our choices, is free will therefore an illusion? Studies have now conclusively shown that the biology of hunger narrows our daily choices and hence what we believe to be “free will”. This is because humans simply cannot reason a way out of a ghrelin surge. Raw hunger can therefore be considered as a lens into true human nature itself.
Still, hope remains. It is important to be aware of the insidious power of hunger which can control us like puppets. Yet all the studies on the effects of hunger indicate that hunger’s grip can be mitigated by mindful eating and regular meals. So the next time you feel indecisive or irritable, ask immediately: “Am I hungry?” If the answer is “Yes”, have a nice healthy snack and a calming cup of tea at once.
In many such situations, research has shown that alleviating hunger is the best way towards reclaiming autonomy over your thoughts.
There is a caveat though, which applies to those people who feel constantly hungry all the time. Such a situation is a potential sign of some form of metabolic disorder. This is an issue which needs to be addressed urgently before it becomes a more significant malady. In the meantime, according to science, such people may be prone to making lots of ill-judged decisions.
Regardless, you should now know why you should never undertake any important decisions on an empty stomach and definitely not undertake shopping trips while hungry.
The views expressed here are entirely the writer’s own.
