GLP-1 Second-Order Effects
20 points
19 hours ago
| 2 comments
| HN
The first-order effects of GLP-1 drugs are obvious: people lose weight, Novo Nordisk and Eli Lilly print money. But what happens when 10-15% of the adult population is on weight-loss medication within a decade? The downstream consequences are less discussed and almost certainly not priced into anything.

In 2018, United Airlines switched to lighter paper for its inflight magazine. One ounce per copy. Across 4,500 daily flights, that saved 170,000 gallons of fuel a year [1]. Airlines think about weight at this level of granularity because fuel is their single largest variable cost.

Average weight loss on semaglutide is around 35 pounds per person. If 12% of passengers on a typical 737 have been on the drug, that's roughly 750 fewer pounds per flight, the equivalent of shaving the weight off 12,000 magazines. United spent months optimizing paper stock to save $290,000 a year in fuel. GLP-1 adoption across the flying population could quietly save them an order of magnitude more, and ticket prices don't adjust down when passengers get lighter.

The food supply chain is more obvious but larger in scale. If a big share of the population eats 20-30% less, demand for calories drops. Not a shift in preferences toward salads. A pharmacological reduction in how much people eat, period. The food industry has dealt with changing tastes before. It has never faced a demand shock from the medical system.

Health insurance has a subtler problem. The pitch for GLP-1 coverage is that the drugs prevent expensive conditions downstream: diabetes, heart disease, joint replacements. Probably true. But in America's fragmented insurance market, the company paying for the drug today probably isn't the one insuring that patient in five or ten years. The savings land on someone else's balance sheet. That mismatch could slow adoption by years on its own.

Obesity correlates with lower workforce participation and higher absenteeism. If GLP-1s meaningfully reduce obesity rates, aggregate labor supply goes up. More people working, fewer health-related absences. That's a macroeconomic stimulus, except nobody frames it that way because it comes from a pharmaceutical company rather than from Congress.

Early data suggests GLP-1s reduce cravings for alcohol, nicotine, and gambling too. Phase 2 trials for opioid use disorder are underway. A weight-loss drug that accidentally dents Diageo's revenue and casino foot traffic was not in anybody's original investment thesis for Ozempic.

The effect I find hardest to think about is the psychological one. Weight has been tangled up with shame, identity, and social hierarchy for centuries. What happens to body positivity, the social dynamics of attractiveness, the entire cultural machinery around diet and discipline when weight becomes something you manage with a prescription? I don't have a good framework for it. Nothing comparable has happened before.

The market is treating this as a pharma story. The drug companies will capture a fraction of the total value created and destroyed. The rest redistributes across food, airlines, insurance, labor markets, and social behavior. Nobody's model probably covers all of that at once.

[1] https://www.cbsnews.com/news/united-hemispheres-magazine-print-edition/

EDIT: Formatting

7777777phil
18 hours ago
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This essay pulls together a few threads from pieces I've written over the past months on my blog, where I dig into rabbit holes like GLP-1 economics among other things.

If the pharma side interests you, I just wrote up Novo's rise and fall as Europe's most valuable company:

https://philippdubach.com/posts/novo-was-europes-most-valuab...

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malshe
17 hours ago
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Thanks for sharing. I quickly skimmed through the latest article on Novo and it looks quite interesting. Bookmarked for later exploration.
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butlike
19 hours ago
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GLP-1 drugs, as I understand it, reduce appetite. They don't magically add nutrients to the body. Of course the body will reduce cravings for alcohol, nicotine, and gambling. Nutrients would be prioritized over the poisons such as alcohol and nicotine. Additionally, why would the body prioritize what it considers fruitless dopamine release (gambling) when there are no nutrients coming in. The body literally can't afford to sit around and gamble since that resource isn't directly transferrable into food. It's literally in a starvation state.

But please, tell me how it's better than finally doing some exercise and eating right.

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falcor84
18 hours ago
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How did you get from reduced appetite to starvation state? I'm not on one of these drugs myself, but from friends I've been talking to, it seems like (after a bit of dosage tuning) it's reducing their appetite to what would be expected from a person who never was obese. So they do lose weight relatively rapidly, especially at the start, but I don't see why we should equate weight loss with starvation.

As for "how it's better", - the answer is clearly that unlike "exercise and eating right", these drugs are leading to positive behavioral change at scale. I'm perhaps slightly exaggerating, but to the best of my knowledge, no other substance over the last several thousand years has had such a clear positive effect on humanity as a whole.

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butlike
16 hours ago
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Still don't understand why we need positive behavioral changes "at scale," but I'm going to leave it at: if it works, I'm happy for you.
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trio8453
15 hours ago
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Because currently we negative self harming behavior at scale, it seems very clear.
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xorbax
18 hours ago
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So you went from know it "reduces appetite" to make a bunch of conjectures about why it affects other things

> But please, tell me how it's better than finally doing some exercise and eating right.

Because it actually works well?

Good ol' fashioned gumption doesn't work, no matter how crankily and haughtily you say it. GLP-1s do

Also, you don't mention why the things you listed are bad. Any weight loss will require a calorie deficit, which has the same "starvation" you're so aghast at.

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butlike
16 hours ago
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Lack of resource adds stress to the body, plain and simple. Exercising without a caloric deficit can build muscle. Weight loss without exercise is all loss no gain while maintaining a stressful state on the body.

And "good ol' fashioned gumption" does work, at least for me. (Sample size: 1)

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mft_
15 hours ago
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Define “stress”.

Calorie restriction is demonstrably life-extending in multiple species (that it’s feasible to test it in).

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