Would you be surprised to find out that in the United States today, about 88 million adults over the age of 18 have pre-diabetes?
Well, according to the National Diabetes Statistics Report, that number is a surprising fact.
Given my interest and personal experience with intermittent fasting, I decided to investigate if pre-diabetics could somehow benefit from incorporating intermittent fasting into their lifestyles.
With that in mind, the goal of this article is to dissect the findings of a journal article published in Cell Metabolism that discusses the potential impacts of intermittent fasting on pre-diabetes and overall cardiometabolic health.
It is not my intent to prescribe nor promote intermittent fasting for the treatment of prediabetes, as I am not a licensed medical professional.
However, dissecting this article as a dietetic student will be personally interesting and informative.
What Does the Study Look At?
Studies that have researched intermittent fasting have revealed several cardiometabolic benefits associated with it.
However, there has been conflicting evidence as to whether those benefits are solely due to weight loss.
To bring clarity to this issue, researchers Sutton et al. conducted a study published by Cell Metabolism in 2018.
In this study, researchers looked at the cardiometabolic benefits of early time-restricted feeding (eTRF) and whether those would still occur even if no weight loss took place.
TRF is a type of intermittent fasting where a person’s feeding window is limited to 10 hours or less per day.
Previous studies indicate that restricting food earlier in the day was associated with improved fasting glucose, insulin resistance, weight loss, lower cholesterol, and lower inflammation.
According to Sutton et al., studies have shown that the body’s circadian rhythm, also known as the body’s “clock”, creates an optimal metabolic environment for eating food earlier vs later in the day.
For this reason, researchers of this study chose eTRF so feeding would align with the participant’s natural circadian rhythm.
How Did They Do It?
To conduct this trial, researchers narrowed down 934 volunteers to 8 male participants between the ages of 47 and 65.
These men all had prediabetes at the start of this trial.
For the initial 5-weeks, researchers instructed participants to adhere to an eTRF schedule where they ate within a 6-hour window, with their last meal being no later than 3:00 pm.
Participants could choose to have breakfast routinely each day at any time between 6:30 am and 8:30 am. Lunch and dinner were subsequently served in 3-hour increments.
For example, if participants chose to eat breakfast at 8:00 am, lunch would be served at 11:00 am and dinner would be served at 2:00 pm. To ensure that the participants did not gain or lose weight, they were required to only eat the meals provided by the research team while under close observation during feedings.
The 5-week eTRF schedule was followed by a 7-week washout period where the participants could return to their normal eating habits.
Participants then returned for the second 5-week control arm of the trial where they ate the exact same meals they had during the first 5 weeks, except within a 12-hour eating window.
For example, if participants routinely chose to eat breakfast at 8:00 am, lunch and dinner would subsequently be served at 2:00 pm and 8:00 pm.
What Did They Find?
Researchers discovered that eTRF had the following benefits:
- eTRF significantly lowered insulin levels and improved insulin sensitivity and beta cell responsiveness.
- eTRF showed to have lasting benefits due to consistently low insulin levels observed through the wash out period and into the second 5-week arm of the study.
- eTRF lowered participants’ blood pressure significantly, and therefore could potentially be used as a tool to support lowering blood pressure.
- Researchers observed a reduction in lipid peroxidation. This is an indicator that eTRF significantly reduces oxidative stress; and therefore could potentially reduce the risk for atherosclerosis.
During this study, no weight loss was observed in these pre-diabetic overweight men. All the cardiometabolic improvements observed were independent of weight loss and food intake.
In summary, the results of this study show that eating in alignment with the body’s circadian rhythm paired with intermittent fasting could be an effective way to potentially help manage pre-diabetes and prehypertension.