If you have searched for a GLP-1 diet, you were probably hoping for a list of rules. New UK data suggests the truer picture is a kitchen, not a rulebook. One person starts a GLP-1, and the whole household's shopping basket quietly changes with her.
What happened
NIQ (NielsenIQ), working with IGD, published the numbers on 23 July 2026. It pairs IGD survey work with NIQ Homescan purchase data over 24 weeks to June 2026.
GLP-1 use among UK individuals has reached 8%, a rise of 3.1 points in nine months. Households with at least one user climbed from 9% to 12% in six months. And 80% of those households said the medication had a moderate to large effect on how everyone in the home eats.
Inside GLP-1 households, 42% reported eating more protein and 34% more fibre. Meanwhile 44% cut back on takeaways, 39% reduced highly processed food, and 31% moved to simpler, lighter meals. In the till data, impulse categories fell 6.1% by unit while fresh food volumes held steady. A third expected to spend more on vitamins and supplements.
The quiet reframe hiding in the data
Look at what went up and what went down. Two things rose: protein and fibre. Everything else fell.
That is not a diet in the usual sense. Nobody added a rule about what they were forbidden to eat. The medication had already done the restricting. What these homes did instead was decide what was worth the small amount of appetite left.
This is what most GLP-1 diet advice gets backwards. On these medications the risk is rarely overeating. It is under-eating protein and losing muscle, because a quarter to a third of the weight lost can be lean mass without deliberate protein and resistance training. A sensible GLP-1 eating plan is a protection plan.
The supplements finding points the same way. When total food falls sharply, so does everything dissolved in it, which is why nutrient gaps are worth watching.
What it means for you
If your appetite is switched off, every bite now has a job.
- Protein first, at every meal. Roughly 25-35g per sitting, eaten before anything else on the plate, is the highest-value habit you have. See what to eat on a GLP-1.
- Fibre gently, with water. Fibre is the other thing these households increased, and it helps, but adding it fast without fluid is a common route to constipation.
- Two short strength sessions a week. Protein is the raw material. Loading your muscles is the instruction to keep it.
- Cook once. The spillover here is good news: higher-protein, less-processed food is not a special medical diet. It suits the rest of the house too.
What to do with this
Shopping habits change faster than advice does. If your basket is changing, the useful thing is a protein number to fill it against.