ISLAMABAD, JAN 24 (ONLINE): Intermittent fasting has gained popularity over the last few years due to its potential health benefits, including weight loss in the short term.
One method of intermittent fasting is time-restricted eating where a person eats for a certain number of hours in a day and fasts for the remaining time.
A new study has found following an “early” time-restricted pattern where fasting runs from about 5:30 pm until about 10 a.m. the next morning helps improve blood sugar regulation and reduce abdominal subcutaneous fat amounts.
Over the last few years, intermittent fasting has gained in popularity as studies show it potentially provides health benefits such as preventing type 2 diabetesTrusted Source, weight loss, improved heart health, and possibly a lower risk for Alzheimer’s disease.
“Intermittent fasting is a simple and practical nutritional strategy that is both easy to follow for participants and relatively easy to prescribe,” Jonatan R. Ruiz, PhD, full professor at the Faculty of Sport Sciences at the University of Granada in Spain told Medical News Today.
“[Intermittent fasting] has been shown to induce modest reductions in body weight, improve cardiovascular health, and align well with long-term daily life practices. Further research is essential to explore its broader effects on metabolic health, disease prevention, and overall well-being in different populations.”
— Jonatan R. Ruiz, PhD
Ruiz is the co-lead author of a new study recently published in the journal Nature MedicineTrusted Source that reports following an “early” time-restricted intermittent fasting pattern — where a person eats for a set amount of hours and fasts for the remaining time — where fasting runs from after 5 p.m. until about 10 a.m. the next day is more beneficial for improving blood sugar regulation, as well as reducing the amount of abdominal subcutaneous fat just under the skin.
Does the timing of fasting matter?
For this study, researchers recruited almost 200 participants between the ages of 30 and 60 years of age, and with a body mass index (BMI) over 32.
All participants were randomly assigned to one of four time-restricted fasting groups: early fasting (food consumed between a median of 9:45 a.m.-5:30 p.m.), late fasting (food consumed between a median of 2:20 p.m.-9:30 p.m.), self-selected fasting, or treatment as usual. Study participants also received nutrition education on the Mediterranean diet and healthy lifestyles.
“Research from animal models suggested that aligning food intake with circadian rhythms could enhance metabolic efficiency and improve health outcomes,” Ruiz explained.
“We wanted to investigate whether these findings translate to humans and how the timing of the eating window — early, late, or self-selected — affects weight loss, fat distribution, and cardiometabolic health in men and women with overweight or obesity,” he said.
Early fasting reduces amount of abdominal fat
Upon analysis, Ruiz and his team found that all fasting groups, regardless of the time-restricted fasting method, had more weight loss — on average 3-4 kg — compared to the usual treatment group.
“This finding underscores the efficacy of time-restricted eating as a simple, non-restrictive dietary approach for weight management. The results demonstrate that time-restricted eating can be an effective strategy for reducing body weight, regardless of the timing of the eating window, offering flexibility for individuals to choose an approach that fits their lifestyle,” Ruiz said.
Scientists also discovered that study participants in the early fasting group had a greater reduction in the amount of abdominal subcutaneous fat, as well as significantly improved fasting glucose levels and overnight glucose.
“The greater reduction in abdominal subcutaneous fat observed in the early fasting group highlights the potential metabolic advantages of aligning food intake with the body’s natural circadian rhythms. This finding suggests that early time-restricted eating could be particularly beneficial for improving fat distribution and reducing obesity-related risks.”
— Jonatan R. Ruiz, PhD
“Our next steps involve investigating the long-term effects of time-restricted eating on bone density and other key health-related parameters. Additionally, we aim to explore whether combining time-restricted eating with exercise offers greater benefits than either intervention alone for managing body weight and composition, reducing ectopic fatTrusted Source, and improving cardiometabolic health,” he added.
More research on time-restricted diets needed
MNT had the opportunity to speak with Mir Ali, MD, a board certified general surgeon, bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA, about this study.
“This is a good study, though the sample size was relatively small,” Ali commented.
“There has been evidence for some time of the benefits of intermittent fasting. Continued research will define those benefits further and help delineate the optimal fasting schedule. I would like to see more research into time-restricted eating and different types of diets. Ideally, it would be helpful to know which diet is most effective with time-restricted eating,” he added.
What’s the best intermittent fasting method for me?
MNT also spoke with Monique Richard, MS, RDN, LDN, a registered dietitian nutritionist and owner of Nutrition-In-Sight, for her tips on how readers can figure out what is the best intermittent fasting for them, especially if they want to lose weight and reduce abdominal subcutaneous fat.
“Aside from meeting with a registered dietitian nutritionist (RDN) to understand the specific nutrient, hydration, and lifestyle medicine recommendations your body may need most, everyone can benefit from doing some simple and safe self-experiments,” Richard detailed.
HOW TO FIGURE OUT THE BEST FASTING WINDOW FOR YOU
“If your work and social schedule allow, choose a time to declare ‘kitchen closed,’ or eating time is done for the day. Maybe 8 pm to 8 am is the window that would work best for your schedule. Test out how this may feel for you for 4-6 weeks. Ask yourself if this is sustainable, manageable and appropriate for you and your needs? How is your mood, energy, (and) cognitive function?”
— Monique Richard, MS, RDN, LDN
Other tips Richard offered include planning out mealtimes and knowing what to have for each meal to help meet nutritional needs and safeguard against hunger attacks.
“Scaling back on snack foods available in your cupboards, fridge, and pantry can cut down on the temptation and desire to reach for those comfort foods while watching your favorite show after your evening meal,” she continued.
“Set an alarm on your phone to remind you that the eating hours of the day are done. Use apps, food diaries, and friends to help make this a game or enjoyable challenge. Take a moment to assess your day and schedule — what are some obstacles or challenges that may hinder this being able to work for you?” she added.
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