Are supermarket ready meals actually unhealthy?
A straight answer: it depends far less on the fact that it is a ready meal than on salt, portion size and what else you ate that day. Here is what the evidence actually supports, and what it does not.
The category is not the problem
A chilled salmon fillet with vegetables and a deep-fried breaded thing in the same chiller are both ready meals. Averaging them tells you nothing useful.
The question that actually predicts anything is the ordinary one: how much salt, how much saturated fat, how big is the portion, and how often. The packaging is not doing the damage.
Salt is the consistent finding
Across surveys of the category, salt is where ready meals reliably sit high, and it is high for structural reasons rather than careless ones — preservation, water control and texture all lean on it.
UK guidance is a maximum of 6g of salt a day for adults; the NHS sets that out alongside how the traffic lights work, and Action on Salt publishes category surveys if you want to see how a shelf compares. One meal carrying a large share of a day's allowance is the thing to notice.
On ultra-processed food
You will see ready meals filed under "ultra-processed", usually via the NOVA classification developed at the University of São Paulo. NOVA groups foods by how much industrial processing they have had rather than by nutrients.
It is a genuinely useful lens and it is also contested — critics point out that the group is broad enough to contain both a supermarket lasagne and wholemeal sliced bread. Observational evidence linking high UPF intake to poorer outcomes is substantial; whether processing itself is the cause, or whether it travels with salt, sugar, fat and portion size, is not settled. Anyone telling you it is settled, in either direction, is ahead of the evidence.
What actually helps
Nothing exotic. More of the dish being the thing it is named after, a portion sized to you rather than to a tray, and less salt — which happens automatically when you season at the end instead of preserving for a fortnight.
The Eatwell Guide is the boring, reliable version of this and is worth more than most of what is written about processed food.
Which is the honest case for cooking it
Not that ready meals are poison. They are not. It is that cooking the same dish yourself changes salt, portion and proportion in one move, costs less per serving once you are making two, and tastes better because you serve it immediately.
That is a good enough argument without needing the scary version.
Questions people ask
Straight answers
Are ready meals bad for you?
Not inherently. Eaten occasionally, as part of a diet with enough vegetables and fibre, a ready meal is unremarkable. The concerns are salt, portion size and frequency — none of which are unique to the format.
Are the additives dangerous?
At permitted levels they have been assessed as safe by EFSA and the UK equivalent. The more useful question is what each one is doing, and the answer is nearly always shelf life or texture — jobs that do not exist in your kitchen.
Is a homemade version definitely healthier?
Only if you make it so. You control salt, fat and portion, which is the opportunity. It is entirely possible to cook something richer than the packet.
How much salt is too much in one meal?
Against a 6g daily maximum, a main meal carrying more than about a third of that is worth noticing — particularly if the rest of the day includes bread, cheese or sauces, which is where most of the remainder usually hides.
The format is not the problem. The salt and the portion are.
Photograph the packet and cook the version where you decide both.
Free to try. Three copies a month, no card.