It’s Stanford time, baby: 8-hour time-restricted press releases linked to a 91% higher risk of hype

Adam Pollack writes:

You and the blog readers might find this interesting: https://newsroom.heart.org/news/8-hour-time-restricted-eating-linked-to-a-91-higher-risk-of-cardiovascular-death.

Yesterday, my friend was very concerned for me after he found out I usually don’t eat breakfast. He told me it’s dangerous. I thought it was as simple as not being hungry for a few hours after I wake up.

He showed me the above press release from the American Heart Association newsroom. I have never seen the results of an abstract for a poster publicized like this. It even made it to CNN (https://www.cnn.com/2024/03/19/health/intermittent-fasting-pros-cons-wellness/index.html). Both the press release and the CNN article emphasize that the findings are preliminary. For example, press release says “As noted in all American Heart Association scientific meetings news releases, research abstracts are considered preliminary until published in a peer-reviewed scientific journal.”

This doesn’t make me feel better about the situation. Let’s pretend this analysis was conducted perfectly (whatever that means). How would the AHA newsroom & CNN report the results if this was peer-reviewed and published? From the newsroom quote above, I get the sense that if it’s in the peer-reviewed scientific journal the press release wouldn’t have any caveat. Maybe they’ll even recommend people change their lifestyles and diets?

I’m being a little disingenuous because the editor’s note from the date after the first press release tells readers they should always consult with their doctor before making changes to their health regimens. Wait, why is there an editor’s note the day after a press release that provides full poster presentation details?? I’m guessing this caused an uproar to some degree in the community. In general, there’s a lot to unpack from this about science communication and the role of science in informing decisions. I’d be most interested in a discussion on your blog about those points, though I’m sure that the poster could inspire some nice statistical discussion too (https://s3.amazonaws.com/cms.ipressroom.com/67/files/20242/8-h+TREmortality_EPI+poster_updated+032724.pdf). For example, the press release reports the authors “were surprised to find that people who followed an 8-hour, time-restricted eating schedule were more likely to die from cardiovascular disease” and it turns out that’s one of 4 effects (look like interaction effects) w/ p < .05 across all the comparisons they make.

The press release refers to “those who followed an 8-hour time-restricted eating schedule, a type of intermittent fasting,” but from the poster, we see that this “eating duration” variable is the average eating duration for the two dietary recall days in the survey. Of the 414 people in the study who reported less than 8 hours averaging those two days, 31 died of cardiovascular disease during the period of the study. In comparison, the reference group is 12-16 hours, which included 11,831 people, of whom 423 died of cardiovascular disease. (31/414)/(423/11831) = 2.09. The estimated risk ratio is 1.91, which they estimated from a a hazard regression adjusting for a bunch of variables including demographics, smoking, and drinking but also total energy intake, body mass index, and self-reported health condition status.

Looks like noise mining to me, but, hey, all things are possible.

Based on what I see in the paper, the statement, “people who followed an 8-hour, time-restricted eating schedule were more likely to die from cardiovascular disease,” does not seem like an accurate description of the data. How you ate in two days of a survey is hardly an “eating schedule.”

Also they say, “Our study’s findings encourage a more cautious, personalized approach to dietary recommendations, ensuring that they are aligned with an individual’s health status and the latest scientific evidence,” which sounds like gobbledygook. You don’t need a statistical analysis to know that, right?

The press release quotes someone else as saying, “Overall, this study suggests that time-restricted eating may have short-term benefits but long-term adverse effects.” B-b-but . . . if they only asked about how people ate for 2 days, in what sense is this telling us about long-term effects? He does follow up with, “it needs to be emphasized that categorization into the different windows of time-restricted eating was determined on the basis of just two days of dietary intake,” and I’m like, yeah, but then how do you get away with that first statement? OK, he is at Stanford Medical School.