Three diets. Three passionate communities. Wildly different claims. We let the RCTs decide.
Here’s the thing most people miss about this topic.
Evidence Scorecard
| Keto | Mediterranean | Carnivore | |
|---|---|---|---|
| RCTs | 50+ | 200+ | 0 |
| Weight loss (short) | Best | Good | Unknown |
| Weight loss (1yr+) | Same as others | Same | Unknown |
| Heart health | Mixed | Best (PREDIMED) | Unknown |
| Longevity | No data | Strong (Blue Zones) | No data |
| Sustainability | 40-50% quit 1yr | 70%+ maintain | Unknown |
The Winner
Mediterranean diet wins on total evidence, long-term health, and sustainability. Keto wins short-term weight loss. Carnivore has zero controlled evidence.
Related: evidence-based supplement guide
The real answer: the best diet is the one you maintain for 10+ years. For most people, that is not keto or carnivore.
My take: the research points in a clear direction here.
Does this match your experience?
Last updated: 2026-04-03
Your Next Steps
- Today: Pick one idea from this article and try it before bed tonight.
- This week: Track your results for 5 days — even a simple notes app works.
- Next 30 days: Review what worked, drop what didn’t, and build your personal system.
Disclaimer: This article is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with any questions about a medical condition.
About the Author
Written by the Rational Growth editorial team. Our health and psychology content is informed by peer-reviewed research, clinical guidelines, and real-world experience. We follow strict editorial standards and cite primary sources throughout.
References
- Estruch, R., et al. (2018). PREDIMED trial. NEJM.
