Appetite for disruption 🍽️

There are drugs, and then there are drugs that change the world. The pill, statins, Viagra. GLP-1s may belong in that category of superstar pharmaceuticals.

For most of history, appetite was fixed. Businesses could stimulate it, exploit it, but they couldn’t dial it down. Now individuals can. If millions start eating less, drinking less, weighing less, and moving more, the second-order effects start to spread well beyond weight loss.

Fixed inputs

Roughly two in five American adults are obese (BMI above 30), and for decades medicine had little to offer them. When it comes to weight loss, diet especially, and exercise, do work, but if it were so straightforward, everyone would be doing it. In fact, if exercise were a drug, it would be considered a miracle drug. But ain’t nobody got time for that. And even if we convince ourselves we have the time, sticking to it is a pain. Just visit a gym on the 1st of February. At the same time, previous weight loss drugs produced modest results and sometimes unpleasant side effects.

Then semaglutide came along. In a landmark 2021 trial, patients lost 14.9% of their bodyweight over 68 weeks, against 2.4% for those only on a 500-calorie daily deficit and 150 minutes of weekly activity. Using Eli Lilly’s (LLY) tirzepatide, a 2025 trial saw patients lose 20.2% of their weight after 72 weeks, versus 13.7% on semaglutide. Those are substantial amounts of weight loss. 

Nil by mouth

GLP-1 helps control blood sugar, slows the rate at which food leaves the stomach, and signals to the brain you’re full, which reduces appetite. Scientists first identified the ‘incretin effect’ in the 1960s after noticing swallowed glucose stimulated more insulin than injected glucose. GLP-1, one of the gut hormones involved, was identified later, but the natural hormone disappears from the bloodstream within minutes, so its effects don’t last long enough to be useful. Researchers solved that by modifying the molecule so it broke down more slowly, turning it into a drug that could last days.

The first practical breakthrough came via the Gila monster, a lizard native to the Southwestern United States, whose venom contains exendin-4, a peptide that behaves like GLP-1. A synthetic version became exenatide, approved for type 2 diabetes in 2005. Weight loss was initially a useful side effect but is now the basis for what Morgan Stanley (MS) thinks could become the largest drug class in history, with annual sales exceeding $100bn by 2030.

There’s a long history of drugs where a side effect becomes a treatment in its own right. Sildenafil was developed for angina before researchers noticed another marketable effect. It became Viagra. Minoxidil began as a blood pressure drug before it was a treatment for baldness. Bupropion was developed as an antidepressant but patients taking it were also more likely to quit smoking.

Mass market

Novo Nordisk (NVO) and Eli Lilly have since built enormous franchises around household names like Ozempic, Wegovy, and Mounjaro. By late 2025, 12% of American adults were taking a GLP-1, up from 6% 18 months earlier, while 18% had used one at some point. Among 50-to-64-year-olds, current use was 22%.

A US survey found 21% of households contained a GLP-1 user, more than double the proportion 16 months earlier. Grocery spending among those households was down 5.5%, but apparel spending was up 9.9% not least because 73% of users reported a change in clothing size.

Portion control

The decline in grocery spending falls hardest on calorie-dense categories such as snacks, baked goods, and confectionery. Which is good for one’s health. But bad for a food industry built around Super Size Me portions, afternoon snacks, cheeky desserts, and a little something for the ride home. Decades of innovation in packaging and flavour engineering all designed to make us gobble down rubbish when we’re not hungry.

A 2026 report from PwC reveals 70% of UK GLP-1 users were spending less on snacks and confectionery, while 60% spent more on fresh food, 54% more on high-protein products, 40% more on vitamins and supplements, 30% more on fitness, and an uplift in clothing sales, with 40% spending more.

In a GLP-1 world, we may see smaller portions, higher protein, more fibre, better nutrient density, and products which generate more revenue per calorie. If customers eat 10% less but spend more on healthier food, companies could sell less food without losing as much revenue.

Last orders

Early studies suggest GLP-1 users may experience reduced alcohol cravings, perhaps because they influence reward pathways in the brain as well as slowing gastric emptying. Morgan Stanley has taken the possibility seriously enough to slim down its alcohol holdings, and the firm believes booze consumption among GLP-1 users could fall as much as 75%, thanks to fewer drinking occasions and fewer drinks each time.

Just 10% penetration among overweight Americans would cut total US alcohol demand by roughly 6%, according to Morgan Stanley. While that 75% is a big assumption, even a much smaller effect would matter to an industry facing weak demand from younger customers and a shift towards health and moderation.

While some studies and trials have been encouraging, particularly around alcohol, the evidence is far from settled. A 2026 meta analysis found no significant effect on alcohol-free days or cigarette consumption, despite promising signals elsewhere.

Belt tightening

Morgan Stanley’s research shows 70% exercising frequently after starting GLP-1 vs 35% before. Losing 15kg or 20kg makes walking, running, and exercising easier and more enjoyable. That could redirect spending towards trainers, sportswear, gyms, and active leisure.

Travel and leisure could eventually move in the same direction. In the short term, there’s a countervailing force because the drugs themselves cost hundreds of pounds or dollars a month, leaving less discretionary income for restaurants and concerts and the like.

Most GLP-1 users were currently spending about the same on out-of-home entertainment. But there’s been an increase in users reporting positive body image, and improved confidence and mobility could tilt spending towards get-up-and-go holidays and leisure rather than trips built around eating and drinking. 

Health dividend

Semaglutide has reduced heart attacks, strokes, and other serious heart problems by around 20% in high-risk overweight and obese patients, while newer indications have extended GLP-1 therapies into sleep apnoea and liver disease. GLP-1s are being investigated for Alzheimer’s and other neurodegenerative diseases, with promising signals but no proven clinical benefit yet.

There may be lower future demand for cardiovascular care, CPAP machines, bariatric surgery, and other treatments associated with obesity. On the other hand, a patient who loses enough weight to stave off a heart attack might become eligible for a knee or hip replacement, live longer, and consume more healthcare later.

Fit for work

US research has estimated employees with obesity miss around three more days of work a year than employees at healthy weight, costing tens of billions of dollars. A 2026 paper using Danish data found GLP-1 treatment reduced long-term sickness absence by 17.3%.

In Britain, the government estimates obesity is associated with roughly four additional sick days per worker a year and around £4.9bn of annual productivity losses from absenteeism. If GLP-1s remove some of that burden, an employer paying for weight loss drugs is not only buying lower future medical costs but more days at work. Better health could keep some in work for longer, particularly in jobs where obesity contributes to disability or early retirement.

All the small things

GLP-1s are microeconomic disruptors. The smartphone is one too. It wasn’t just a new product category but changed the economics of cameras, taxis, maps, music, ads, retail, and more. 

While GLP-1s remain expensive and stopping them often means putting the weight back on, as supply catches up with demand and prices fall, their effects will ripple through society in myriad and unexpected ways.

If obesity is managed rather than ‘cured’, consumer habits will pivot for good. A world built on more, more, more will have to learn how to sell to a consumer who now wants less.