- Previous studies have shown that time-restricted eating (TRE) and high-intensity interval training (HIIT) in isolation can reduce cardiac metabolic risks in overweight or obese individuals.
- A recent randomized controlled trial showed that a 7-week TRE regimen combined with HIIT resulted in greater improvements in long-term glycemic control and body composition in overweight/obese women, compared to TRE or HIIT only.
- These results suggest that the combination of TRE and HIIT could be a potential long-term strategy for improving cardiovascular health in obese/overweight women.
Individuals with obesity and insulin resistance are at increased risk of developing cardiovascular diseases, including diabetes, hypertension, and other cardiovascular diseases. Lifestyle interventions that involve dietary modifications and increased levels of physical activity can reduce cardiac metabolic risks, but adherence to these prescriptions is often difficult.
A new study was published in cell metabolism suggests that overweight/obese women who observed a regimen of time-restricted eating (TRE) combined with high-intensity interval training (HIIT) for seven weeks showed greater improvement in metabolic health than either intervention alone.
Furthermore, these participants demonstrated high levels of adherence to TRE and HIIT alone or in combination.
Co-author of the study Dr. Trane MuldA researcher in physiology at the Norwegian University of Science and Technology said:
“Our findings on improved body composition, metabolic health, and higher adherence rates suggest that women at risk for cardiac disorders can improve their health with the combined TRE + HIIT program, and that it is safe and beneficial for this population.”
Strategies to lose and maintain weight primarily include increased physical activity and dietary changes. However, studies have shown that weight loss strategies such as
This has led to an increased interest in alternative weight loss strategies such as TRE and HIIT.
Time-restricted eating involves restricting the intake of calorie-containing foods to a specific time window, usually 6 to 12 hours, during the day.
TRE does not limit the types of foods that can be eaten or the intake of calories during the eating window. This can promote better compliance than the standard weight loss strategy of calorie restriction.
“TRE offers a relatively simple way to change eating habits by focusing only on meal timing and usually results in an automatic reduction in energy intake without deliberate effort,” said Dr. Moldt.
On the other hand, high-intensity interval training involves repeated short bouts of high-intensity exercise interspersed with periods of rest or low-intensity activity.
Previous studies have shown that TRE and HIIT in isolation can Improve cardiovascular And the
However, there is a lack of evidence for the effects of the combination of TRE and HIIT in obese individuals with a more sedentary lifestyle.
In the current randomized controlled trial, researchers examined the combined effect of time-restricted eating and HIIT in overweight/obese women of childbearing age.
The researchers randomly assigned 131 overweight/obese women enrolled in the study to one of the four groups—combined TRE and HIIT, TRE alone, HIIT alone, and a control group without intervention. HIIT consisted of three sessions of treadmill exercise per week supervised by the researchers, while TRE involved restricting caloric intake to a 10-hour window during the day.
These interventions lasted for seven weeks and participants underwent a range of assessments to assess glycemic control and cardiovascular health before and at the end of the intervention.
Initial evaluation included
The researchers found that the isolated and combined TRE and HITT participants showed no differences in glucose tolerance compared to the control group.
However, participants in the TRE and HITT group showed greater decreases in . levels
All three interventions resulted in lower body weight and greater loss of total and visceral fat mass compared to the no-intervention control group.
Furthermore, the combined TRE and HIIT group showed a twofold greater reduction in total and visceral fat mass compared to TRE and HIIT in isolation. This is noteworthy because visceral fat, the fat that surrounds the abdominal organs, is a risk factor for diabetes and other metabolic diseases.
The researchers then examined levels of adherence to these interventions over the seven-week study period. Individuals in the TRE alone and the combined TRE and HIIT groups adhered to a 10-hour eating window for more than six days a week on average during the study.
Similarly, participants in the HIIT alone and the TRE and HIIT groups completed more than 90% of the exercise sessions. The researchers caution that more research is necessary to determine whether these high rates of adherence to HIIT can be sustained over a longer period.
“We believe that the high adherence rates reported in our study are due to careful follow-up of participants and fully supervised exercise sessions. In most real-world settings, such follow-up is not realistic or available,” Dr. Moldt explained.
This study is one of the largest to examine the combined effect of TRE and HIIT. However, the study had some limitations.
The short study duration of seven weeks may not be sufficient to detect differences in metabolic health indicators and measures of glycemic control due to the three interventions.
Dr. Corente PetersonAn assistant professor in the Department of Nutritional Sciences at the University of Alabama at Birmingham said:
The study only took seven weeks, so there may not be enough time to see changes in health, and the study only included women. There is some evidence that intermittent fasting has slightly different effects in men versus women, so we don’t know if the same is true for men. Nor is the study large enough to detect all possible improvements in health. Finally, body fat percentage was not measured with bioimpedance, which is not the best test available for measuring body fat.”
Co-author of the study Dr. John HawleyThe head of the exercise and nutrition research program at the Australian Catholic University in Melbourne agreed with Dr Peterson’s comments about the female-only study and said it should be replicated in males.
Dr Hawley added: “TRE participants reported eating less, so we don’t know if the positive effects of TRE are due to lower energy intake or meal timing per se.”
The researchers are currently engaged in studies to further study the effect of TRE in tandem with HIIT and to address some of the shortcomings of their current work.
More research should investigate the long-term effects of these interventions and their combination. Furthermore, we believe that the high adherence rates reported in our study were due to careful follow-up of the participants and fully supervised exercise sessions. In most real-world settings, this follow-up is not realistic or available. “We are now investigating whether TRE combined with remotely administered HIIT for seven weeks will produce positive health benefits in overweight or obese men and women,” said Dr. Moholdt.
“We are also currently inviting women who participated in the study to attend for new lab tests and to answer questionnaires about adherence and perceptions about TRE and/or HIIT two years after the end of the intervention period,” she added.
“[A] The two-year follow-up study will give us insight into how the TRE and HIIT are maintained beyond the recognition period provided by the study setting, and whether any health benefits initially resulting from the interventions are maintained in the long term. “
– Dr. You are born