Interesting Epidemiological Results for Time Restricted Feeding
Epidemiology is prone to difficulties that arise when attempting to interpret limited data sets, packed with information, but never quite all of the information that would be necessary to see the real story. Try to look at the health differences between people who drink and people who don't, and the sample of those who don't is polluted by former problem drinkers with problematic lives. Try to look at the health differences between obese and non-obese patients, and the non-obese cohort will be polluted by formerly obese people who have lost weight due to poor health and advanced disease. Try to base considerations on body mass index (BMI), and the high BMI groups are polluted by heavily muscled former athletes. And so forth.
Some of these problems are now evident in hindsight and sufficiently debated for researchers to have come to a resolution. No-one uses BMI when height and waist circumference are available. Researchers seek weight history rather than looking only at snapshots in time. But each of these advances can require ten to fifteen years to percolate through the epidemiological community. Even after that point, the old data sets remain the old data sets, lacking modern conveniences. Further, there are always new ways to provoke debate in the framing of data, and provoking debate is a great way to have people cite your paper. So the incentives tend to line up for more of the same in the future.
So to today's epidemiological results, which fly in the face of everything that is known about intermittent fasting and calorie restriction. To grossly oversimplify decades of research, it is starting to look like time spent hungry is beneficial regardless of calorie intake, and all mild forms of calorie restriction, fasting, and time-restricted feeding appear both beneficial and safe. So what might be happening here? How does one find a correlation between time-restricted feeding and greatly increased risk of cardiovascular mortality? If one looks at what the researchers say about the data, it occurs to me that selecting for time-restricted feeding habits in the general population is selecting for people who have been prompted into that course by the perception of needing to lose weight or having received physician guidance to lose weight. Both of those options correlate with being overweight or obese. Thus selecting for unusual dietary habits in this study population may be a good proxy for excess weight.
8-hour time-restricted eating linked to a 91% higher risk of cardiovascular death
Time-restricted eating, a type of intermittent fasting, involves limiting the hours for eating to a specific number of hours each day, which may range from a 4- to 12-hour time window in 24 hours. Many people who follow a time-restricted eating diet follow a 16:8 eating schedule, where they eat all their foods in an 8-hour window and fast for the remaining 16 hours each day, the researchers noted. Previous research has found that time-restricted eating improves several cardiometabolic health measures, such as blood pressure, blood glucose, and cholesterol levels.
In this study, researchers investigated the potential long-term health impact of following an 8-hour time-restricted eating plan. They reviewed information about dietary patterns for participants in the annual 2003-2018 National Health and Nutrition Examination Surveys (NHANES) in comparison to data about people who died in the U.S., from 2003 through December 2019, from the Centers for Disease Control and Prevention's National Death Index database.
The analysis found: (a) people who followed a pattern of eating all of their food across less than 8 hours per day had a 91% higher risk of death due to cardiovascular disease; (b) the increased risk of cardiovascular death was also seen in people living with heart disease or cancer; (c) among people with existing cardiovascular disease, an eating duration of no less than 8 but less than 10 hours per day was also associated with a 66% higher risk of death from heart disease or stroke; (d) time-restricted eating did not reduce the overall risk of death from any cause; (e) An eating duration of more than 16 hours per day was associated with a lower risk of cancer mortality among people with cancer.
From the study description: "Factors that may also play a role in health, outside of daily duration of eating and cause of death, were not included in the analysis." So they didn't even correct for smoking. Smokers are more likely to skip breakfast due to the appetite-suppression. And there are lots of other reverse-causality stories that need correcting for.
The study authors wanted a good headline and didn't care if they mislead many people in order to achieve that. Unethical, in my opinion.
@Nigel
The below study was adjusted for smoking among other things.
Specifically, they adjusted for several cofounding factors: age, sex, history of hypertension, diabetes mellitus Body mass index ,Smoking status . Alcohol status , Education level, Exercise level. Sleep duration, Work - day shift, night shift, or shift work. After adjusting for confounding factors, skipping breakfast significantly increased the risk of mortality from circulatory diseases [hazard ratio (HR) = 1.42] and all causes (HR = 1.43) in men and all causes mortality (HR = 1.34) in women
Yokoyama Y, Onishi K, Hosoda T, Amano H, Otani S, Kurozawa Y, Tamakoshi A. Skipping Breakfast and Risk of Mortality from Cancer, Circulatory Diseases and All Causes: Findings from the Japan Collaborative Cohort Study. Yonago Acta Med. 2016
Erratum in: Yonago Acta Med. 2019 Dec 28;
"An eating duration of more than 16 hours per day was associated with a lower risk of cancer mortality among people with cancer."
Hard to understand how sleeping less than 8 hrs and eating apon waking and just before sleeping is a benefit to those with cancer.