I’ve been overweight for about 30 years. Or at least, I’ve been over the “correct” BMI for my height. I doubt I’ll ever hit the official ideal weight on the NHS tables — and honestly, I don’t care.
If anything, what I illustrate is that the definitions of what is and isn’t a healthy weight are slipping badly out of date. BMI is a blunt instrument. It doesn’t distinguish between fat and muscle, and it’s been criticised for years.
This year The Lancet published a new definition of obesity, widening the criteria to include:
- waist circumference
- waist-to-hip ratio
- waist-to-height ratio
- or having two raised indicators regardless of BMI
- or direct measures of excess body fat via scans
Some people — like me — would no longer be overweight under the new criteria. But others would fall into that category for the first time. In fact, around 70% of Americans.
A study in JAMA looked at 301,026 adults between 2017 and 2023. Under the traditional BMI definition, 43% of participants had obesity. Under the new definition, that jumped nearly 60% to 69%.
For those aged over 70, it reached 78%.
All of this is happening at the same time as US obesity rates, by the old definition, are actually falling — from roughly 39.9% in 2022 to 37% today.
That drop is largely due to the rise of GLP-1 weight-loss drugs.
For the uninitiated, GLP-1s include:
- Ozempic (semaglutide)
- Wegovy (also semaglutide)
- Mounjaro (tirzepatide)
These aren’t classic diet drugs. Users typically lose 15–20% of their bodyweight because the drugs alter how we interact with food: slowing digestion, suppressing appetite, changing reward pathways.
At the same time, other trends are reinforcing the shift — lower alcohol consumption, and a decade-long boom in high-protein foods.
What this means for the UK
Up to 220,000 people can access weight-loss medications on the NHS, but around 1.5 million currently get them privately.
NHS England estimates 2.8 million people would qualify for Mounjaro if supply allowed.
This could have a huge impact on public health — comparable to statins or the fall in smoking.
But here come the caveats. Two big ones.
1. We don’t know how the benefits are distributed.
In the UK and US, life expectancy has split sharply along income, education and geography.
- The well-off and well-educated are living longer.
- Poorer communities face rising morbidity and falling life expectancy.
- In the US, these areas tend to vote Trump.
- In the UK, they correlated with Brexit support.
GLP-1 drugs could easily worsen that gap: the well-off get thinner and healthier; the poor get sicker and heavier.
Making the drugs widely available on the NHS could soften this effect — but in the US, Medicare and Medicaid cuts mean those who need them most won’t get them.
2. The bigger problem: illness is systemic.
Patterns of disease come from society — economics, environment, stress, work, housing, education, food.
But for right-wing ideologues (and a surprising number of wellness gurus), that idea is taboo.
They insist illness is about bad choices, and health is about willpower.
If you’re overweight, you’re weak. If you’re sick, it’s your fault.
The “naturally superior” stay thin and healthy.
It’s nonsense. And dangerous nonsense at that.
People make poor choices. I make poor choices. Everyone does.
But the obesity epidemic in Britain and America is fundamentally about:
- the food people can afford
- how difficult it is to eat healthily
- education
- and a food industry that makes billions from ultra-processed, obesogenic products
Unless those are addressed, we’re stuck in a grim loop:
- a food industry that makes people ill
- a pharmaceutical industry that sells the cure
- and influencers and ideologues who shame the “untermensch” for their failure
Admitting this requires acknowledging the systemic nature of illness — and that is, increasingly, a forbidden idea.
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2840138
https://www.thelancet.com/commissions-do/clinical-obesity
https://www.ft.com/content/b71a1c59-2735-4ec8-b895-59c562edeeac