12/01/2025
MECHANISM vs OUTCOMES — Why “Sounds Scientific” Isn’t the Same as “Actually Helps You”
One of the biggest issues I see in online fitness and wellness content is people confusing mechanistic research with outcomes-based research.
Mechanistic studies tell us how something might work — usually in a petri dish, isolated cells, or rats.
Outcomes studies tell us something far more important:
👉 Does this actually help real humans live longer or healthier?
The problem?
A mechanism can look perfect on paper but fail completely when tested in real people.
Here’s a perfect example that’s everywhere in influencer-land:
🔹 “Coffee raises cortisol, cortisol is bad… therefore coffee is bad.”
Mechanism: Yes, caffeine can temporarily raise cortisol.
Outcome: Massive human studies show coffee drinkers live longer, have lower all-cause mortality, lower risk of diabetes, and improved cardiovascular outcomes.
So the mechanism says “avoid coffee,”
but reality says coffee improves longevity.
This disconnect happens all the time.
Here are a few more classic examples:
🔹 Niacin and coronary artery disease
Mechanism: Raises HDL, lowers LDL — looks incredible.
Outcome: RCTs show no reduction in cardiovascular events and plenty of side effects.
🔹 Antioxidant supplements (vitamin E, beta carotene)
Mechanism: Reduce oxidative stress.
Outcome: Human trials show no benefit and in some cases increased cancer and mortality.
🔹 Testosterone boosters / herbal supplements
Mechanism: Increase LH in rats or stimulate androgen receptors in vitro.
Outcome: In humans? No meaningful change in testosterone or performance.
🔹 BCAAs
Mechanism: Activate mTOR and muscle protein synthesis.
Outcome: In people eating adequate protein, no measurable improvement in muscle growth or recovery.
And here’s the pattern:
Fitness influencers LOVE mechanistic research.
Why?
It sounds smart.
It’s easy to cherry-pick.
And it helps them sell supplements that have never been proven to improve real outcomes.
So you’ll constantly hear:
❌ “This raises a hormone we don’t like.”
❌ “This inhibits an enzyme linked to aging.”
❌ “This increases fat oxidation in rats, so it burns fat.”
Meanwhile, in the actual human trials?
✔️ No fat loss
✔️ No health improvement
✔️ Sometimes even harm
Mechanism ≠ Outcome.
Mechanisms help us generate hypotheses.
Outcomes tell us the truth.
So the next time someone online passionately warns you:
“Don’t drink coffee because it spikes cortisol!”
Just ask:
👉 “Show me the human outcomes data.”
Because your health deserves evidence, not vibes.
