The GLP-1 tsunami isn’t a diet trend – it’s a stress test for the food system

Key takeaways:

• GLP-1 drugs are reducing how much people eat without reducing what their bodies need, exposing widespread gaps in protein, fiber and micronutrient intake.
• Consumers on GLP-1 therapies are buying less food but demanding more nutrition per bite, accelerating shifts toward protein, fiber and portion-smart products.
• For food brands, GLP-1 is less a diet trend than a structural stress test that will reward genuine nutrient density and punish empty calories.

The speed of the GLP-1 rollout has caught almost everyone off guard. Drugs designed to manage diabetes have become mass-market appetite suppressants in the space of a few short years, quietly reshaping how people eat, shop and think about food.

In the US, roughly one in four households already includes a GLP-1 user, based on Circana data, and those households are on track to influence more than a third of all food and beverage sales by the end of the decade. In the UK, Ocado estimates around 2.5 million adults are now using injectable GLP-1s – about one in 25 – with more than one in five saying they’ve considered it.

That kind of penetration doesn’t just tweak demand: it bends it.

What’s striking, though, is how little most consumers understand about what these drugs actually do. Ocado’s research suggests fewer than half of UK shoppers can explain how GLP-1s work. Fewer still understand that the weight loss isn’t purely fat. Around 40% of consumers are aware that muscle loss is part of the equation. The public story is still neat and seductive: eat less, lose weight, feel better. The biological reality is messier and the nutritional fallout is starting to show.

Clinical reviews are now filling in the uncomfortable gaps. A University of Cambridge analysis published in Obesity Reviews found GLP-1 therapy typically cuts calorie intake by anywhere from 16% to nearly 40%. That’s dramatic. But it’s not automatically healthy. The same review warns that lean muscle can account for as much as 40% of total weight lost, particularly when protein intake isn’t actively protected. Calories fall, but so do protein, fiber, vitamins and minerals. Appetite drops but nutritional needs don’t. That mismatch is where trouble creeps in.

This matters because most people were already under-consuming key nutrients long before GLP-1s entered the chat. Fiber intake is chronically low across the UK and US. Vitamin D, iron, calcium, magnesium and several B vitamins routinely miss recommended targets. Now layer appetite suppression on top of that.

Dietitians are increasingly clear that GLP-1 users often need more nutritional focus, not less. Preserving muscle alone can require protein intakes well above standard reference levels – often 1.2 to 1.6 grams per kilogram of bodyweight per day. In reality, many users struggle to hit even a modest protein target per meal, especially when nausea or early satiety kicks in.

Smaller appetites, sharper expectations

Consumers are adapting fast, even if understanding lags behind behavior. In the US, around 15 million adults are currently prescribed GLP-1s and about one in eight has tried them at some point. These households are buying less food by volume, but they’re not disengaging. Quite the opposite. Circana estimates they already account for roughly a quarter of total food sales, despite eating less.

What they’re cutting is revealing. Sugary drinks, impulse snacks and traditional ‘treat’ categories are taking the biggest hits. What’s holding up are products that promise to do something – protein for muscle, fiber for digestion, hydration for side effects, energy without heaviness. Research from ADM shows four in five GLP-1 users are willing to pay more for foods with added health benefits, and two-thirds actively look for attributes they perceive as compatible with appetite suppression.

Portions are shrinking, too. More than half of GLP-1 users say they deliberately choose smaller servings. Nearly half report snacking far less than before. In the UK, Kantar data suggests many GLP-1 users have switched retailers altogether to find products that fit their new eating patterns, while almost a quarter say existing ranges still don’t offer enough nutritionally dense options. Ocado’s own data paints a similar picture: most users understand diet matters, but fewer than half can correctly identify protein and fiber as priorities.

This is the paradox of the GLP-1 shopper. They’re motivated, selective and willing to spend – but they’re navigating a food landscape that was built for volume, frequency and indulgence. When appetite is muted, food has to justify its place. Empty calories don’t survive the cut.

When reformulation moves faster than regulation

Food companies haven’t waited around. Across the US and UK, smaller portions, protein-forward meals and ‘nutrient-dense’ positioning have arrived at speed. Supermarkets are rolling out compact ready meals in the 250g-300g range. Lean proteins are being resized. Frozen aisles are being recalibrated. Even indulgence is being reshaped, with two-bite treats and fortified desserts designed to feel controlled rather than reckless.

From a formulation standpoint, the logic is sound: protein protects muscle; fiber supports digestion and helps manage common side effects; sugar intensity is being toned down as GLP-1 users report heightened sweetness sensitivity; ingredient suppliers are pitching fermentable fibers, resistant starches; and plant and dairy proteins as essential tools for this new eating reality.

But labeling has raced ahead of clarity. In the US, ‘GLP-1 friendly’ has no legal definition. Claims are typically allowed only when backed by standard nutrient statements, but the phrase itself carries a halo effect. A high-protein meal can still be high in sodium or saturated fat; and a badge can imply suitability without standards. Ironically, sales data shows most of these products aren’t even being bought by GLP-1 users. They’re selling a feeling of control, not a prescription-specific solution.

Pricing hasn’t helped the optics. Smaller portions often cost the same as, or more than, larger ‘diet’ meals did previously, effectively raising the price per gram. Critics see shrinkflation dressed up as wellness. Others question whether entirely new products are necessary at all. Couldn’t GLP-1 users just eat less of what already exists? Or does drug-linked labeling risk medicalising food in a way that ultimately confuses more than it helps?

What GLP-1s are really forcing the industry to admit

Strip away the hype and GLP-1s are doing something more profound than suppressing appetite. They’re exposing how much of modern nutrition has relied on overeating to paper over weak nutrient density. When volume disappears, the cracks show.

Economic analyses from Cornell University and PwC point to a 5%-11% drop in grocery spending among GLP-1 households, with discretionary categories like sweet snacks, baked goods and chips hit hardest. Protein-rich foods – yogurt, eggs, nuts, prepared meats – are proving more resilient. That shift may persist even if GLP-1 usage plateaus. Once consumers experience eating less but better, many don’t want to go back.

For bakery and snacks, the implications are uncomfortable. Industry sales data suggests snack purchases among GLP-1 users are down around 6% overall, with sweet bakery products and chips falling faster. That’s billions in lost volume. But it’s also a forcing function. Protein-enriched baked goods, fiber-forward formats, portion-smart indulgences – these aren’t just defensive plays. Done well, they appeal far beyond GLP-1 users.

The real question is whether the industry treats GLP-1 as a marketing hook or a structural reset. Low-calorie and ‘guilt-free’ messaging feels increasingly hollow in a world where every bite has to earn its keep. What resonates now is nourishment, function and satisfaction in smaller amounts.

GLP-1 drugs aren’t just changing how much people eat. They’re changing what food has to do. Brands that respond with substance rather than stickers will still matter in a smaller-plate future. The rest may find that when appetite disappears, so does tolerance for food that doesn’t pull its weight.

Study:

Spreckley, Marie & Ruggiero, Cara F & Brown, Adrian. (2026). Nutrition Strategies for Next‐Generation Incretin Therapies: A Systematic Scoping Review of the Current Evidence. Obesity Reviews. 10.1111/obr.70079.