Intermittent fasting helped people keep weight off for a year
Date:
July 18, 2026
Source:
University of Granada
Summary:
A 12-week intermittent fasting program produced weight-loss benefits that were still visible a year later. Participants who ate within an eight-hour window maintained more weight loss than those who followed their usual longer eating schedule. Both early and late eating windows worked, while early fasting appeared especially helpful for preserving fat loss.
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A 12 week intermittent fasting program may help people maintain weight loss for at least a year after the structured intervention ends, according to research involving the University of Granada (UGR)
Published in Clinical Nutrition, the study followed 99 adults who were overweight or obese. Half of the participants were women. Researchers found that limiting daily food intake to an eight hour period helped participants preserve more of their weight loss than maintaining an eating window of 12 hours or longer
Intermittent Fasting Benefits Persisted for a Year
The researchers examined the popular 16:8 approach to intermittent fasting. Under this method, people fast for 16 hours each day and eat during the remaining eight hours
The lasting benefits did not depend on whether participants ate earlier or later in the day. An early schedule allowed eating between 9 a.m. and 5 p.m., while a later schedule used a window between 1 p.m. and 9 p.m
One year after the intervention ended, both the early and late fasting groups had maintained significantly more weight loss than participants who continued eating across 12 hours or more each day. Those assigned to the early schedule also preserved a larger reduction in fat mass
The findings suggest that time restricted eating may be practical in the short term while also producing effects that continue well beyond the initial program
Tracking Weight and Body Composition
The study appeared in Clinical Nutrition, the official journal of the European Society for Clinical Nutrition and Metabolism. Scientists from the University of Granada (UGR), the Granada Institute for Biomedical Research (ibs.GRANADA), the <a href="https://healthylife7.com/north-star-puts-first-public-hearing-on-calendar/” title=”North Star puts first public hearing on calendar”>Public University of Navarra, and the Biomedical Research Networking Center (CIBER) participated in the research
During the first 12 weeks, all 99 participants received education about following a Mediterranean diet. They were then placed into four groups
The control group continued using its usual daily eating window of 12 hours or longer. The early fasting group followed an eight hour window beginning before 10:00 a.m. The late fasting group used an eight hour window beginning after 1:00 p.m. Participants in the self selected group chose their own eight hour schedule
Researchers measured body weight, fat mass, and fat free mass before and after the intervention. They assessed the same measurements again one year after the program had concluded
The work was part of a broader research project whose primary findings were published in Nature Medicine. Those results showed that participants practicing TRE lost an average of 3-4 kilos more than people who received nutritional guidance alone, regardless of when their eating window occurred
Weight Changes Remained After the Program
Dr. Alba Camacho Cardeñosa, a researcher at the University Joint Institute for Sport and Health (iMUDS) at the University of Granada (UGR) and a postdoctoral fellow at ibs.GRANADA in the Endocrinology and Nutrition Department at San Cecilio University Clinical Hospital, is the first author of the study
She explains that “to date, although we knew that intermittent fasting promotes modest weight loss in the short term, it was unclear whether its effects were sustained over time. By evaluating the participants 12 months after the intervention ended, we demonstrated that the changes in body weight persist.”
The researchers also point to evidence that the routine may be manageable outside a controlled study. They highlight that “a very positive finding is that one in three people decided to continue practicing intermittent fasting on their own during that year of follow-up, suggesting that it is a relatively easy habit to integrate into daily life.”
A Flexible Approach to Weight Management
Researchers from the PROFITH CTS-977 research group at the University of Granada (UGR) led the study through ibs.GRANADA. Professor Jonatan Ruiz Ruiz heads the group
The project also included collaborators from San Cecilio University Clinical Hospital, Virgen de las Nieves University Hospital in Granada, the Public University of Navarra, the CIBER on Obesity (CIBEROBN), and the CIBER on Frailty and Healthy Aging (CIBERFES)
According to the research team, even a 12 week period of intermittent fasting could provide an effective medium term option for weight management among adults who are overweight or obese
Because both early and late eating windows produced lasting benefits, patients may be able to choose the schedule that fits their routines most comfortably. That flexibility could make the approach easier to follow and potentially improve its usefulness in obesity treatment
Research Into Metabolic and Cardiovascular Health
The MP20 group, Biomarkers of Metabolic and Bone Diseases at ibs.GRANADA, studies biological markers and potential treatment targets related to metabolic, bone, and cardiovascular conditions
The group combines bioinformatics with clinical research to create diagnostic tools and assess possible therapies. Its work includes investigating intermittent fasting as a treatment for obesity and associated health problems, along with studying whether bone markers can help predict cardiovascular risk
Through its multidisciplinary and collaborative approach, the group aims to produce research with practical clinical applications
Materials provided by University of Granada. Note: Content may be edited for style and length
Journal Reference:
- Alba Camacho-Cardenosa, Elisa Merchán-Ramírez, Antonio Clavero-Jimeno, Alejandro De-la-O, José María Romero-Noguera, José L. Martín-Rodríguez, Manuel Muñoz-Torres, Idoia Labayen, Jonatan R. Ruiz, Manuel Dote-Montero. Effects of an early, late, and self-selected time-restricted eating intervention on weight loss maintenance in adults with overweight or obesity: A 12-month follow-up of a randomized controlled trial. Clinical Nutrition, 2026; 63: 106706 DOI: 10.1016/j.clnu.2026.106706
Cite This Page:
University of Granada. “Intermittent fasting helped people keep weight off for a year.” ScienceDaily. ScienceDaily, 18 July 2026. <www.sciencedaily.com/releases/2026/07/260718010154.htm>.
University of Granada. (2026, July 18). Intermittent fasting helped people keep weight off for a year. ScienceDaily. Retrieved July 18, 2026 from www.sciencedaily.com/releases/2026/07/260718010154.htm
University of Granada. “Intermittent fasting helped people keep weight off for a year.” ScienceDaily. www.sciencedaily.com/releases/2026/07/260718010154.htm (accessed July 18, 2026).
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