GLP-1 medications have reached a level of household penetration that food and beverage brands can no longer ignore, but the impact on grocery sales is unfolding more gradually than some might expect. According to Big Chalk Analytics’ fall 2025 industry update report, GLP-1 household penetration increased from 11.2% in June to 12.0% in November, underscoring a small but significant shift.
Rick Miller, partner and marketing effectiveness practice lead at Big Chalk, cautioned brands against overestimating how quickly that growth translates into total market disruption. “It’s definitely an increase in users, but it’s not like, ‘Oh wow, suddenly a third of America is on GLP-1s,’” he said.
For CPG brands and retailers accustomed to operating in categories with near-universal household penetration, Miller said context matters.
“This is fast growing, but keep it in context of the total US population,” he said, noting that roughly two-thirds of households still say they will never use the medication.
Smaller pack sizes emerge as a structural shift
One of the clearest signals for manufacturers is accelerated pack-size downsizing among GLP-1 users. In November, GLP-1 users traded down to smaller packs at significantly higher rates than the US average across both indulgent and everyday food categories, according to the report.
For cold cereal, 28.2% of GLP-1 users reported purchasing smaller packs, compared with 18.7% of all US consumers last month. In loose granola, the figures were 27.1% versus 17.0%, respectively. Even in potato chips and soda – categories often assumed to be most vulnerable – the difference was comparable to center-aisle staples.
The shift reflects more than price sensitivity.
“Generally speaking, consumer interest in smaller pack sizes has been on the rise for a couple of years after the big bump in inflation that we saw after the pandemic,” Miller said.
“It was financially driven, but in the last year or so, it’s now trending to be more GLP-1 driven – or you could probably make the case, more health driven in general.”
The presence of GLP-1s in the public consciousness is changing how consumers think about portions.
“Just the fact that the drug exists and that it’s being promoted and that it’s in the public consciousness has people thinking about portion control,” where consumers are “trading down on pack size, for sure,” he emphasized.
Miller added that whether brands are designing specifically for GLP-1 users or reassessing price-pack architecture more broadly, making smaller packs more available and affordable is becoming a long-term expectation rather than a short-term tactic.
Calorie reduction affects more than indulgent categories
Big Chalk estimates that GLP-1 use could drive between 1.3% and 3.1% grocery food volume loss in 2026.
While common logic suggests calorie-dense indulgences will bear the brunt of those cutbacks, Miller said Big Chalk’s findings complicate that assumption.
“We don’t have hard data yet that suggests chips, soft drinks and those things are being cut at a higher rate than other categories,” he said.
Instead, Miller said conversations with GLP-1 users suggest a broader reset. “They’re just eating less in general,” he said. “Because they’re eating less in general, they’re trying to eat healthier things, but they’re really just cutting calories across the board.”
That pattern explains why categories like cereal and granola – often perceived as better-for-you – are also seeing pack-size trade-downs. “There’s just less room in your daily consumption for things that aren’t going to necessarily be helpful to you,” Miller said.
Miller noted that many GLP-1 users appear to view the medication as part of a wider lifestyle shift rather than a standalone fix, which has implications for how brands think about reformulation, portioning and nutrient density.
Planning for growth without overcorrecting
Although Big Chalk expects GLP-1 adoption to continue rising, Miller stressed that “high growth” in the medication category does not automatically translate to mass-market penetration.
“From a total population, household penetration perspective, the growth is a little bit more moderate,” he said.
That distinction is critical for CPG brands. “It’s growing. It’s definitely something you need products for in your portfolio and a good marketing message around ... But keep that growth rate in mind from the perspective of total household penetration,” he said.
In practical terms, Miller advised brands to ensure they have options that naturally appeal to GLP-1 users without assuming the trend will – or should – reshape their entire portfolio overnight.
No one-size-fits-all messaging
Big Chalk’s report calls for more tailored creative and messaging for GLP-1 users, but Miller was clear that there is no universal playbook.
Instead, Miller said brands need to understand how GLP-1 usage intersects with their own consumer base.
“What is the percentage of soda drinkers that are on GLP-1 for your particular soda brand versus the category at large versus the total US population?” he said.
“You can size your market, and you can develop messaging strategy in one fell swoop,” Miller added. “But it’s still going to be yours. You can’t go look at what the brand down the aisle is doing and copy their messaging, because it’s probably not going to work for you.”
As adoption evolves, Big Chalk’s message to CPG brands and retailers is consistent: invest in brand-specific research, treat pack size as a strategic lever and resist the urge to generalize GLP-1 behavior across categories.
