Actually I don’t think that journalist captures the biggest flaw of all, which is the sample size. 20,000 people sounds kind of big, but it’s actually tiny. The problem is that the average age of the population was 49. Heart attacks among people below old age are relatively rare to begin with, and when you are sorting out people who self-report eating on a time-restricted schedule your numbers are going to be minuscule. “91%” is the relative risk, but I don’t see where they report the absolute risk or the absolute numbers. My guess is that a couple instances could be driving that seemingly large figure. Relative risk is meaningless in almost any context (of data reporting) without also understanding absolute risk.