Educational overview · Approx. 4 min read · illustrative, not advice
Four forecasters, one prevalence dataset and one adoption survey. Read the spread between the forecasts rather than the largest number in it.
Prevalence: the addressable population
US adult obesity prevalence was 40.3% during August 2021 through August 2023, with severe obesity at 9.4%, according to CDC and the National Center for Health Statistics. Prevalence was 39.2% in men and 41.3% in women, and highest among adults aged 40 to 59 at 46.4%. Including overweight, 72.4% of US adults aged 20 and over were affected over the same period.
The trend line matters as much as the level. Age-adjusted adult obesity prevalence did not change significantly from 2013-2014 through August 2021-August 2023, while severe obesity rose. This is a large, stable, slowly worsening population, not a spike.
The 40-to-59 concentration is the single most operationally useful number on this page, because it tells you who your marketing is actually speaking to.
Adoption: who is actually using these drugs
KFF's health tracking poll, fielded October 27 to November 2, 2025, found 18% of US adults say they have ever used a GLP-1 drug and 12% are currently using one, up six percentage points in current use since May 2024.
Current use concentrates where you would expect: 45% among adults with diabetes, 29% among those with heart disease, 23% among adults diagnosed as overweight or obese in the past five years, 22% among ages 50 to 64, and 9% among those 65 and over.
The affordability picture inside that user base is the part most operators underweight. Among users, 56% reported difficulty affording the drug and 25% said it was very difficult. Twenty-seven percent had insurance but paid the entire cost themselves. Fourteen percent stopped because of cost. That last figure is a retention problem before it is anything else, and page eleven treats it as one.
Forecasts: read the spread, not the headline
Morgan Stanley Research projects global GLP-1 sales across diabetes and obesity at approximately $190 billion by 2035, more than double 2025 levels. Goldman Sachs Research forecasts the global anti-obesity drug market at approximately $95 billion by 2030, revised down from an earlier estimate of approximately $130 billion. Grand View Research projects the narrower GLP-1 weight-loss segment at approximately $48.8 billion by 2030, on an 18.5% compound annual growth rate from 2025.
These are not contradictions. They are different definitions across different horizons: class-wide including diabetes, anti-obesity drugs generally, and the GLP-1 weight-loss segment specifically. Anyone quoting only the largest of the three at you is selling, not analysing.
The Goldman downward revision is the most instructive item here. A serious forecaster cutting a category estimate by roughly a quarter is a signal about pricing pressure and adherence assumptions, and it belongs in your planning more than the maximum headline does.
What this data does not tell you
It does not tell you what a business in this category will produce. Market size is the size of a category's drug sales, not of your service revenue, and there is no defensible arithmetic that bridges from one to the other for a single operator.
We will not build that bridge, and you should treat anyone who does as having told you something important about themselves. Atlas has no Franchise Disclosure Document, and without one any figure describing what a partner might earn is an unsubstantiated earnings claim regardless of how it is labelled.
What the data does tell you is that the population is large and stable, adoption is rising, use is concentrated in identifiable segments, and cost is the dominant friction inside the existing user base. Those four facts shape a service model. They do not forecast one.
Numbers we deliberately omit
Three figures circulate widely in this category that we will not repeat. A frequently quoted 2025 category sales total with per-product breakdowns could not be confirmed against IQVIA or company filings. No reliable public national count of semaglutide or tirzepatide prescriptions dispensed exists, and retail-discount fill-growth percentages describe one publisher's own fill base rather than national volume. And the commonly stated count of states with corporate practice of medicine laws rests on inconsistent methodology; the Milbank brief itself declines to state a count.
Omitting a number you cannot source is not a gap in a market analysis. It is the analysis.
- CDC / National Center for Health Statistics, Data Brief No. 508 — US adult obesity prevalence 40.3% and severe obesity 9.4% during August 2021-August 2023; 39.2% men, 41.3% women; 46.4% among ages 40-59; age-adjusted obesity prevalence did not change significantly from 2013-2014 through August 2021-August 2023 while severe obesity rose. (source) [VERIFIED]
- CDC FastStats (NHANES) — 72.4% of US adults aged 20 and over had overweight, including obesity, during August 2021-August 2023. (source) [VERIFIED]
- KFF Health Tracking Poll (fielded October 27-November 2, 2025) — 18% of US adults have ever used a GLP-1 drug, 12% currently, up six points since May 2024; current use 45% with diabetes, 29% heart disease, 23% diagnosed overweight or obese in past five years, 22% ages 50-64, 9% ages 65+; 56% of users reported difficulty affording, 25% very difficult, 27% insured but paid entire cost, 14% stopped due to cost. (source) [VERIFIED]
- Morgan Stanley Research — Global GLP-1 sales across diabetes and obesity projected at approximately $190 billion by 2035, more than double 2025 levels. (source) [VERIFIED]
- Goldman Sachs Research — Global anti-obesity drug market forecast at approximately $95 billion by 2030, revised down from approximately $130 billion. (source) [VERIFIED]
- Grand View Research — The GLP-1 weight-loss segment is projected to reach approximately $48.8 billion by 2030 at an 18.5% CAGR from 2025. (source) [VERIFIED]