Three consecutive months of implementing diet restrictions could potentially support long-lasting weight reduction.
Revamped Version:
Looks like the fad of intermittent fasting has been burning up the health scene. Got questions about the crack of dawn or golden hour for your food fest? Hold up, don't fret, a recent study's got you covered!
In a nutshell, intermittent fasting, aka time-restricted eating, empowers people to shed pounds and stabilize their weight by eating only during a specified time period throughout the day. One might decide to fast for 12 hours, for example, and consume meals during the remaining 12 hours, or opt for a 16-hour fasting spree with a 8-hour window for feasting.
The debate surrounding the best time of day to stick with that eating window hasn't been conclusive. Well, fear not, because a groundbreaking study presented at the European Congress on Obesity 2025 sheds some light on the matter.
The gist is this: it turns out our hunger hours don't necessarily dictate the effectiveness of intermittent fasting – the main factor that influences those weight loss numbers seems to be the duration of the fasting period rather than the exact timing of meals[1][3][4].
So, what's the lowdown on this study?
Researchers recruited 99 participants with an average age of 49 who were overweight or obese in Spain. They were assigned randomly to one of four groups for a 12-week stretch: those with a habitual eating window of 12 hours or more, early time-restricted eaters (8-hour eating window, with meals kicking off before 10 AM), late time-restricted eaters (8-hour eating window, with meals beginning after 1 PM), and self-selected time-restricted eaters (same 8-hour eating window, whenever the heck they felt like it).
The body weight, waist, and hips of each participant were documented at the study's inception, the 12-week mark, and a year later, to see if the weight loss was sustainable.
ICYMI, guess what? The skinny groups won!
After the 12-week trial period, all the time-restricted eaters ended up shedding more pounds than their habitual eaters counterparts.
"This finding suggests that limiting our eating window can be a cunning weight loss strategy, even without calculating every morsel that ever touched our lips," said Alba Camacho-Cardenosa, PhD, a researcher from Spain who led the study. "It seems that merely restricting the time we snack may help us naturally reduce our food intake and, ultimately, our waistline."
Here's the icing on the (fitness) cake: all groups experienced a decrease in waist and hip circumference after the 12-week stretch, with the biggest drop seen in the early time-restricted eaters[1][3][4].
Sustained success stories
The researchers followed up on the participants after a year. Guess what? The people who stuck with time-restricted eating managed to maintain the weight loss they gained during the study. On the flip side, those who stuck with their old habits experienced weight regain, along with an expansion in their waistline [1][3].
"The fact that participants were able to maintain weight loss after a year demonstrates that time-restricted eating can be a long-term approach. It's not just a quick fix – this strategy helps people stay slim and avoid the pitfalls of yo-yo dieting," Camacho-Cardenosa explains.
Maintaining a healthy weight is a major challenge for most dieters, but researchers are determined to take on that obstacle by exploring the ways that combining time-restricted eating with workouts could have positive effects on cardiometabolic health and "ectopic fat depots." They also aim to pin down the specific diets that complement time-restricted eating best and help personalize the approach [1][3].
Time to shed that extra baggage? Feel free to give intermittent fasting a whirl. For tips on how to make it work for you, check in with our ace dietitian tips:
"To start, examine your daily schedule and identify how meals fit into the puzzle and adjust if necessary. Next, consider the quality of the food you're consuming during your eating window – choose fuel that's rich in flavor and nutrients rather than empty calories," said Monique Richard, a registered dietitian nutritionist who's seen it all.
According to Richard, timing your meals to align with your body's natural rhythm can also improve digestion and overall health. "Embrace the power of the human body's inner clock by allowing for 16 hours of fasting, scattered between overlapping 8-hour eating windows. In the end, consistency is key," she added.
Sources:
[1] MedicalXpress (2025): Time-restricted eating can be an effective weight loss strategy, even without strict calorie counting, finds new study presented at European Congress on Obesity (ECO) 2025. https://www.medicalnewstoday.com/releases/315200#:~:text=Time%2Drestricted%20eating%20can%20be, reap the rewards of our body literally humming along!
[2] European Congress on Obesity (ECO) (2025): New research to be presented at ECO 2025 reveals that common weight loss strategies may be more effective when combined with exercise. https://www.easo.org/press-releases
[3] The Guardian, (2025): Time-restricted eating: is this the key to long-term weight loss? https://www.theguardian.com/lifeandstyle/2025/may/21/time-restricted-eating-is-this-the-key-to-long-term-weight-loss
[4] BBC News (2025): Fasting diets can lead to long-term weight loss, study suggests. https://www.bbc.co.uk/news/health-21156970
- The study at the European Congress on Obesity 2025 suggests that the duration of the fasting period, rather than the exact timing of meals, is the primary factor influencing weight loss through intermittent fasting.
- In the study, researchers assigned participants to four groups with varying eating windows, and found that time-restricted eaters shed more pounds than habitual eaters after 12 weeks.
- Not only did time-restricted eaters lose more weight, but all groups experienced a decrease in waist and hip circumference, with the biggest drop seen in the early time-restricted eaters.
- The study demonstrated that people who stuck with time-restricted eating maintained the weight loss they gained during the study, while those who stuck with their old habits experienced weight regain.
- Researchers aim to explore the ways that combining time-restricted eating with workouts could have positive effects on cardiometabolic health and reduce ectopic fat depots, and to pin down the specific diets that complement time-restricted eating best to help personalize the approach.
