Time restricted eating linked to higher risk of death?
Time-restricted eating has gotten increased attention in recent years as a way to lose weight and improve health. Studies have proven the benefits of fasting. However, not eating for 24 hours or more sounds like a daunting task for most. Time-restricted fasting became a more appealing option. Studies revealed many benefits from short-term time-restricted fasting, however, a recent preliminary study has stated that 8-hour time-restricted eating is linked to a 91% higher risk of death from cardiovascular disease. 
While this is a striking percentage, this study had multiple limitations. In this article, we will talk about the study design, limitations, findings, and what future research will look like as a result.
What is time-restricted eating?
Time-restricted eating is a form of fasting that allows you to eat whatever you want within a certain time frame. The most common schedule is 16:8 — where you fast for 16 hours and eat within 8 hours.
This type of restricted eating is often done between 2 and 7 days a week. Doctors and patients usually use time-restricted eating to reduce weight and improve health markers.
Previous studies were done on the short-term benefits of time-restricted eating. Many health parameters were improved by time-restricted eating, including but not limited to:
- Improved insulin sensitivity
- Reduced body weight and prevented extra weight gain
- Lower blood pressure
- Decreased serum triglycerides, total cholesterol, and LDL cholesterol levels
- Increased anticancer activity of chemotherapy agents
- Reduced cancer cell proliferation and progression
- Improved mitochondrial function
- Preserving lean muscle mass
All of these benefits make sense as to why it is such a common practice for people trying to get healthier or lose weight. However, a recent study has revealed that these benefits may not be the case long term.
Study Design
The findings of this study were released during the American Heart Association’s Epidemiology and Prevention│Lifestyle and Cardiometabolic Scientific Sessions 2024, March 18- 21, in Chicago.
The study followed 20,000 Americans. They compared those who followed an 8-hour time restriction diet to those who did the typical 12-16-hour eating window. They looked at a few different databases to get portions of their information:
- Dietary patterns between 2003-2018 for participants from NHANES
- Data on deaths and their causes from 2003-2019 from both
- Centers for Disease Control (CDC)
- Prevention’s National Death Index database
The average age of participants was 49 years old. Those participating needed to be at least 20 years old when beginning the study in 2003. All participants self-reported their dietary habits throughout a median of 8 years and a max of 17 years.
The majority (73.3%) of participants were non-Hispanic white and the gender split was 50/50.
What the study found
This study found that long-term 8-hour time-restricted eating may be linked to a 91% higher risk of cardiovascular death.
What was interesting was that they compared all-cause, cardiovascular, and cancer-related deaths. All-cause and cancer-related deaths were not associated with the 8-hour time-restricted eating window. They actually showed a lower incidence of cancer-related death in 16+ hour eating windows.
People who had cardiovascular disease and cancer, however, were in a higher risk category for cardiovascular deaths when practicing long-term 8-hour time-restricted eating.
Limitations and Future Research
Researchers in the study have cautioned against reporting this information until further studies can be done. There are a few limitations to this study design and there is absolutely a need for more research to be done.
Preliminary studies are to test a hypothesis and then be further tested. However, with such a high mortality percentage linked to the research, this is a big deal for people to consider — especially with the rising incidence of diabetes, cardiovascular and metabolic conditions, and obesity.
In this study, one of the first limitations is that people were self-reporting their data. This is a quick and less costly way to conduct research. By having the participants record their own information, it allows them to live a mostly normal life while participating. However, if you’ve ever tried tracking your food intake, you’ll know how inconsistent this can end up being.
Another limitation is that it wasn’t clearly indicated how many days per week participants were doing 8-hour time-restricted eating. The requirement was for a minimum of 2 days per week, however, if some people followed it for 2 days while others followed it for 7 days a week, this can contribute to differing outcomes.
Something else to consider is that this is not a peer-reviewed, published study. So while the data is interesting and was presented well, it still needs to be peer-reviewed before considering it legitimate data.
The last and probably most important limitation to consider is that this is showing an association NOT a causal relationship. A causal relationship means there is no denying that one thing is causing the other. An association merely points out that the two things are happening together and compared to similar data it is more associated with one than the other (i.e. all-cause vs cardiovascular vs cancer mortalities in this case).
So while this study did show a striking association between 8-hour time-restricted eating and cardiovascular death, there is a lot of research to untangle and figure out before researchers and doctors can truly utilize this information when working with patients. However, it is a good bit of information to have in mind when talking about time-restricted eating with patients. If someone has a higher risk of or is currently suffering from cardiovascular conditions, offering them a longer eating window might be a better place to start.
Future studies should be peer-reviewed so the data can be considered when treating patients. We feel it is important to share these types of studies regardless because it’s important for patients to know everything they can while considering what to do with their dietary decisions. Future studies will determine more specifications and likely have different study designs to get to the bottom of this information.
Follow along with Atrantil or the American Heart Association for more details when they are released.
If you’re looking for more information about different types of fasting, check out the following blog posts we have on the subject. Also, keep in mind that Atrantil is a safe option to take while fasting so your microbiome stays nourished and can keep itself healthy without breaking your fast.