19,000 adults says it's an observational study, which means there's a good chance that people go on these diets as an attempt to fix an existing problem.

Has this been replicated, or is the report detailed enough to attempt replication?

Direct link to Report

Summary Results and Conclusion:

Results

During a median follow-up of 8.1 years, compared with eating duration of 12–14 h, eating duration <8 h was robustly associated with higher cardiovascular mortality (HR, 2.35 [95 % CI, 1.39–3.98]), but not with all-cause and cancer mortality. The positive association with cardiovascular mortality remained consistent across 8 subgroups stratified by race/ethnicity, socioeconomic factors, and smoking status, and survived 14 sensitivity analyses. However, the association with all-cause mortality did not survive many sensitivity analyses.

Conclusions

Although a positive association was observed between eating duration <8 h and cardiovascular mortality, further research is required to understand whether this risk is attributed to the short eating duration itself or residual confounding resulting from its contributing factors.

The comments on HN indicate the significant brain rot of the techno-fascist user base. So many commenters who don't know anything about statistics, acting as though their anecdotal evidence has value, and casting doubt on medical science...