Intermittent fasting has been sold as a near-magical path to better health. From celebrity MMA stars to podcast empires it has been branded as the diet that trims fat sharpens focus and transforms energy levels. Yet new evidence suggests that compressing meals into an ultra-restricted eating window may not be as safe as its most vocal supporters claim—especially for heart health.
The eight-hour eating window often framed as the 16:8 intermittent fasting plan entered the mainstream in the past decade. While researchers initially described it as time-restricted eating (TRE) it was athletes entertainers and influencers who pushed it into popular culture.
Joe Rogan for example publicly endorsed intermittent fasting back in 2019. On his widely viewed podcast he described how fasting eliminated his mid-day energy crashes improved his body composition and helped him add lean muscle. Rogan embraced a 16-hour fasting window paired with a high-protein low-carb diet heavy on wild game and vegetables. For him fasting wasn’t just about calorie control—it was a philosophy of metabolic efficiency paired with a belief that modern diets are overloaded with sugar and refined carbs.
He was not alone. UFC legend Georges St-Pierre has also been a vocal proponent crediting intermittent fasting with helping him control weight while extending his career longevity. Even UFC president Dana White has gone on record calling fasting part of his health turnaround at one point describing it as a strategy that helped him reverse medical issues and drop significant weight.
With figures like these championing the lifestyle intermittent fasting gained a reputation not just as a diet but as a discipline tied to athletic performance masculinity and self-optimization.
For years the scientific evidence seemed to back up these claims—at least in the short term. Clinical trials suggested that fasting could reduce inflammation improve blood sugar control and support weight loss. But most of those studies were brief often lasting less than a year and they rarely looked at long-term health outcomes.
That gap in knowledge is exactly what makes new research so important. A recent study published in *Diabetes & Metabolic Syndrome: Clinical Research & Reviews* analyzed eating patterns of nearly 20000 U.S. adults from the National Health and Nutrition Examination Survey (NHANES) between 2003 and 2018.
The results? People who confined eating to fewer than eight hours a day had a 135% higher risk of cardiovascular mortality compared to those with a 12–14 hour eating window. This association held up across socioeconomic racial and lifestyle subgroups and remained significant even after extensive sensitivity analyses.
Interestingly the same pattern was not observed for all-cause mortality or cancer deaths—meaning the increased risk appears specific to the cardiovascular system.
Researchers caution against rushing to conclusions but several theories exist. Ultra-restricted eating windows may disrupt circadian rhythms elevate stress hormones or encourage binge-like eating patterns that strain cardiovascular health. Others note that people adopting fasting are not always following nutrient-dense diets; an eight-hour window filled with red meat processed snacks or alcohol may compound risks rather than alleviate them.
Another layer is psychological: the rigidity of fasting schedules can encourage rigid behavior leading individuals to push beyond sustainable limits. While these effects may not be visible in short-term trials they could emerge over decades of adherence.
The contrast between scientific caution and influencer enthusiasm highlights a broader cultural issue. Figures like Rogan St-Pierre and White have helped normalize fasting as a lifestyle of discipline and strength but their experiences are not controlled trials. What “works” for elite athletes or wealthy media figures—who also pair fasting with supplements professional training and medical oversight—may not translate safely to the general population.
The study’s authors themselves stress that more work is needed before firm conclusions can be drawn. Still the possibility that fasting could increase heart disease risk should give pause to those adopting the diet simply because their favorite MMA star or podcaster swears by it.
Intermittent fasting may deliver short-term benefits in weight loss and metabolic health but the emerging evidence of cardiovascular risk suggests it’s not a universal solution. As with many influencer-driven health trends the danger lies in treating personal anecdotes as scientific fact.
The lesson is clear: before adopting any rigid dietary practice—no matter how popular—long-term consequences must be considered. Influencers may help bring ideas into the mainstream but it’s science that should guide whether those ideas are worth following.
References
Chen M. Xu L. Van Horn L. Manson J. E. Tucker K. L. Du X. Feng N. Rong S. & Zhong V. W. (2025). Association of eating duration less than 8 h with all-cause cardiovascular and cancer mortality. *Diabetes & Metabolic Syndrome: Clinical Research & Reviews* 103278. https://doi.org/10.1016/j.dsx.2025.103278
