Pulse ·
Why alcohol sends you straight to the chips: the science
University of Sydney researchers analysed dietary data from 9,337 Australian adults and found that alcohol triggers FGF21 — a liver hormone signalling protein insufficiency — producing cravings for savoury foods. This is why the chips arrive when the drinks do.
The catch: most bar snacks (chips, crackers, processed dips) mimic savoury flavour without delivering protein, so the craving persists. Choosing actual protein (eggs, legumes, lean meat) satisfies FGF21's signal more efficiently and tends to reduce total calorie intake. The study is observational; individual responses vary.
Most people have experienced the aperitif effect without knowing its name: a drink arrives, and within the hour so do the chips. You weren’t hungry. Now you’re halfway through a bowl of something you didn’t plan to eat, and the bowl is empty before the decision felt conscious.
Research published this week from the University of Sydney proposes a biological mechanism for this experience — and the finding is specific enough to be practically useful, even if it comes with the usual observational-study caveats.
What the research found
The team used a method called mechanistic ecological modelling — a framework designed to test physiological hypotheses against real-world dietary data rather than controlled laboratory conditions. Their dataset: dietary records from 9,337 Australian adults, large enough to model population-level patterns in eating behaviour after alcohol consumption.
The central finding: alcohol consumption triggers the liver to release FGF21 — fibroblast growth factor 21 — a hormone that signals to the brain that the body is protein-deficient. This is the same hormonal signal that fires during protein restriction or certain metabolic stresses. In evolutionary terms, alcohol is a carbohydrate-derived substance with no nutritional protein content, so the body reads it as a gap.
The brain’s response to that signal is a savoury craving — specifically, the kind of umami-rich, savoury flavour associated with protein-dense foods: meat, eggs, legumes, dairy. The body is asking, in the only language it has, for protein.
The ultra-processed problem
Here is where the mechanism becomes interesting from a nutrition standpoint. The foods most readily available in drinking contexts — chips, crackers, processed dips, bar snacks — have been engineered to be savoury and umami-rich. They register on the flavour receptors associated with protein. But they deliver almost none. They are what the researchers describe as “protein decoys”: products that mimic the sensory signal of protein without satisfying the underlying biological need.
The result is a feedback loop. You eat the chips. The FGF21 signal doesn’t resolve. You reach for more chips. You’ve consumed significant fat and refined carbohydrate and your body is still waiting for the protein it requested.
The researchers found this effect was specific to protein-poor savory foods — not sweet foods, not foods generally. The biological drive is directed, not diffuse. That specificity is what makes the finding clinically interesting rather than just confirmatory of “drinking makes you eat more.”
Both-and
This research is genuinely useful framing — but it’s worth holding it at the right level of certainty. The study is observational and population-based. It shows a pattern and proposes a mechanism; it does not prove the mechanism in individuals. FGF21’s role in human appetite signalling is an active area of research, and the field has not yet reached consensus on exactly how the FGF21-brain axis functions in real-world eating conditions as opposed to controlled animal studies.
There is also the broader context of alcohol and nutrition, which the framing of “eat better snacks when drinking” can inadvertently minimise. Alcohol itself is a nutrient-poor, calorie-dense substance with well-established dose-dependent health harms. The finding that swapping chips for eggs might reduce net calorie overconsumption on a given occasion is useful information; it does not reframe the relationship between alcohol intake and metabolic health overall.
What it does do is make the snack behaviour less mysterious, and give it a biological rather than purely willpower-based framing. For patients who experience significant dietary dysregulation in drinking contexts — and who have been told to “just make better choices” — understanding the FGF21 mechanism may actually be more useful than another exhortation to eat less.
My two cents
The practical takeaway here is simple enough to share in a consultation: if you drink alcohol and find yourself reaching for snacks, your liver is sending a protein signal. Ultra-processed savoury foods hijack that signal without resolving it. A small amount of actual protein — a boiled egg, roasted chickpeas, some cheese — will satisfy the craving more efficiently and leave you eating less overall.
That’s not a cure for alcohol’s other downstream effects. But it is a mechanistically plausible and accessible nudge, and in the complex conversation around nutrition and alcohol, accessible nudges are underrated.
For anyone already thinking about their metabolic health — and a 45-year-old woman’s relationship with alcohol, sleep, visceral fat, and hormonal change is a constellation worth considering carefully — this is one more reason why the “just one glass” context matters less than what the glass is sitting next to.
Verdict: maybe — the mechanism is plausible and practically useful, but the evidence base is early and individual variation is real.