Roughly half of what Australians eat every day has been engineered in a factory. That's not an exaggeration. And the research on what it's doing to us is genuinely alarming.
Picture a typical weeknight. You're tired, it's dark, and the idea of cooking anything real feels like a lot. So you grab something from the freezer, or swing through a drive-through, or crack open a packet of something that has a shelf life longer than your car loan. Sound familiar? That's not a personal failure. That's by design.
Ultra-processed foods (UPFs) now make up somewhere between 38% and 60% of daily calories in most high-income countries. They're not just junk food — they're entire meal categories engineered to be cheap, fast, shelf-stable, and impossible to stop eating.
And the evidence of what they're doing to us has hit a point where I think we need to talk about it plainly.
The mortality numbers are hard to ignore
A major 2024 umbrella review published in the British Medical Journal pulled together 45 large-scale studies and found links between high UPF intake and 32 different health outcomes — everything from heart disease to depression to early death.
50%
A separate US study tracked over 540,000 adults for nearly 23 years. People eating the most ultra-processed food were 10% more likely to die from any cause compared to those eating the least. A Spanish study found an even steeper result — a 62% higher hazard of death, with each additional daily serving of UPF bumping mortality risk up by 18%.
These are not small numbers. And they held up even after researchers adjusted for overall diet quality — meaning the processing itself seems to be part of the problem, not just the fact that UPFs tend to be low in nutrients.
It's not just about what's in them — it's how they mess with your brain
Here's the part most people get wrong. The common story is that junk food is addictive because sugar and fat flood your brain with dopamine. Simple, satisfying narrative. Also not quite accurate.
Researchers used PET scanning to actually measure dopamine responses in the brain after people drank an ultra-processed, high-fat, high-sugar milkshake. The result? No significant dopamine spike in the reward centres of the brain at all.
So why is it so hard to stop eating this stuff? Because UPFs are engineered to maximise wanting, not satisfaction. The artificial flavours, textures, and smells trigger dopamine before you even eat — through packaging, advertising, aroma. By the time you're actually eating it, your brain's already been primed. And the post-eating satisfaction is weak, so you keep going.
Chronic consumption also rewires how your gut and brain communicate about hunger and fullness. Over time, your normal appetite-control signals get blunted, and overconsumption becomes the new baseline.
What it does to your gut is even worse
A healthy gut microbiome runs on fibre. Beneficial bacteria like Akkermansia muciniphila and Faecalibacterium prausnitzii ferment fibre into short-chain fatty acids — particularly butyrate — which keeps your gut lining intact and your immune system calm.
UPFs are almost entirely devoid of real dietary fibre. Without it, beneficial bacteria decline. Pathogenic bacteria take over. And without butyrate, the cells lining your gut start to lose their structural integrity. The protective mucus layer degrades. Bacterial toxins that were supposed to stay in your gut start leaking into your bloodstream.
Leaky gut
Those leaking toxins trigger systemic inflammation. That inflammation reaches your brain, suppresses a key protein called BDNF that's essential for mood, memory, and cognitive function, and sets the conditions for depression, anxiety, and cognitive decline. There's a direct biological pathway from a UPF-heavy diet to worsening mental health. Not a theory — a mechanism.
The structural problem nobody wants to talk about
It's tempting to frame this as a personal choice issue. Eat better. Cook more. Make smarter decisions. But that framing ignores a lot.
In the US, around 20% of the population lives in food deserts — areas with low income, no car, and no access to a real supermarket. The options are dollar stores, where the inventory is almost entirely shelf-stable, ultra-processed items. And research shows that UPF prevalence in those discount stores is up to 42% higher than in well-stocked supermarkets.
SNAP participants in the US (the food assistance program) get roughly 54.7% of their daily calories from UPFs. That's not because they're making poor choices — it's because EBT cards can be used on packaged shelf-stable food but not on freshly prepared meals. The system structurally funnels people toward processed food.
And contrary to what you might think, time isn't actually the biggest driver of UPF consumption. USDA research found that work hours had very little effect on convenience food demand. What actually drives it is price. UPFs are cheaper — and they've been getting cheaper relative to whole foods for decades.
So what do we do?
Honestly, the research points clearly toward structural fixes rather than individual willpower: taxing ultra-processed foods, subsidising whole foods, reforming food assistance programs so fresh food is actually accessible rather than just technically purchasable, better front-of-pack labelling that reflects processing rather than just nutrients. None of that is coming fast.
But here's what changed things for us on a practical level: having an actual reason to care.
When Daniel was diagnosed with ankylosing spondylitis, we started looking hard at food not as a moral category — not "eating clean" or "being healthy" in the abstract — but as something with real, measurable downstream effects on a specific body. The No Starch Diet isn't for everyone, and we've never claimed it is. But working out what actually affects how you feel on a given day makes it very hard to keep handing that decision over to a factory.
Not everyone has an AS diagnosis as a forcing function. But the research we've covered here is, genuinely, its own forcing function — if you let it be. Fifty percent higher cardiovascular mortality risk. A direct biological pathway from UPF consumption to depression and cognitive decline. A food system designed from the ground up to work against your body's natural signals.
You don't have to be perfect. You don't have to cook everything from scratch every night. But knowing the mechanism — understanding why it's hard to stop, and what it's actually doing — is a different starting point than "try to eat better."
And that, really, is what this blog is about. Not perfection. Not rules. Just trying to understand what's going on, and making slightly better decisions because of it.
Convenience food isn't just bad for you in the abstract way that "too much of anything is bad." It's specifically engineered to override your body's natural signals, and the evidence now clearly shows it's shortening lives. That's worth taking seriously — even if the fix isn't as simple as just cooking more broccoli.