Restricting dietary intake for a 3-month span potentially promotes lasting weight loss.
The Booming Trend of Intermittent Fasting: Does the Time of Day Matter?
Over the past few years, the dietary pattern of intermittent fasting, or time-restricted eating, has gained significant popularity. The question remains, however, what time of day to schedule the eating window of this popular weight loss method.
Research presented at the European Congress on Obesity (ECO) 2025 reveals that time-restricted eating remains effective for long-term weight loss, regardless of when the eating window occurs during the day.
Setting up the Study
A group of researchers from Spain recruited 99 participants with an average age of 49 who were considered to have overweight or obesity. The study participants were randomly assigned to one of four groups for 12 weeks: habitual eating (eating window of 12 hours or more), early time-restricted eating (8-hour eating window that starts before 10:00 am), late time-restricted eating (8-hour eating window that starts after 1:00 pm), and self-selected time-restricted eating (8-hour eating window whenever the participant wanted it).
The scientists recorded each participant's body weight, waist and hip circumference, at the beginning of the study, after 12 weeks, and 12 months after the study's conclusion.
Weight Loss Results
After 12 weeks, the researchers found that all time-restricted eating groups lost more weight than the habitual eating group. All groups also experienced lower hip and waist circumferences, with the largest decline seen in the early time-restricted eating group.
At the 12-month mark, the participants in the habitual eating group experienced a weight gain, while all three time-restricted eating groups maintained a weight loss. Those in the habitual eating group also showed an increase in waist circumference after 12 months, while those in all three time-restricted eating groups remained lower.
Sustaining Long-term Weight Loss
"The fact that participants were able to maintain weight loss after 12 months shows that time-restricted eating can be a sustainable long-term approach," explained lead author Alba Camacho-Cardenosa, PhD. "It means that this strategy does not just help people lose weight, but it can also help them maintain it, which is a major challenge in most weight loss programs."
Time-restricted Eating as a Practical Long-term Strategy
Finding new, effective, and pragmatic strategies for long-term weight management is crucial to improving health outcomes and reducing the risk of chronic diseases associated with obesity.
It's important to note that the timing of the eating window did not seem to be crucial for achieving weight loss, as long as the fasting period was consistently maintained and the overall calorie intake was reduced.
Personalizing the Time-restricted Eating Approach
Further research will aim to explore how time-restricted eating combined with exercise affects cardiometabolic health and ectopic fat depots and identify which types of people benefit most from specific eating windows to further personalize the approach.
For those considering trying intermittent fasting, Monique Richard, MS, RDN, LDN, offers the following tips:
- Navigate your daily schedule to find a workable eating plan.
- Keep in mind how the body works, and consider the benefits of routines and specific mealtimes.
- Be intentional with the why, how, what, and when of your eating habits.
Time-restricted eating can be a practical, long-term solution for sustainable weight loss, providing people with a manageable way to improve their health and reduce the risk of chronic diseases.
- Within the realm of health-and-wellness, time-restricted eating, a popular method for weightloss, offers long-term effectiveness for weight management, according to a study conducted by researchers from Spain.
- The significant findings from the study revealed that all time-restricted eating groups, regardless of the eating window's timing, lost more weight than the habitual eating group.
- Remarkably, those in the time-restricted eating groups were able to maintain weight loss for 12 months, challenging the commonly cited issues in most weight loss programs.
- As a long-term strategy, time-restricted eating is considered not just helpful for weight loss but also for weight-management, improving health outcomes, and reducing the risk of chronic diseases associated with obesity.
- To maximize the benefits of intermittent fasting, it's essential to align the approach with one's lifestyle, nutritional needs, and fitness routine, following tips such as personalizing the time-restricted eating window and maintaining overall calorie intake reduction.
