A 12-week intermittent fasting program may help maintain weight loss for at least a year after completing a structured intervention, according to a study involving the University of Granada (UGR).
Published in clinical nutritionThe study followed 99 adults who were overweight or obese. Half of the participants were women. Researchers found that restricting food intake to eight hours a day helped participants maintain more weight loss than maintaining a meal window of 12 hours or more.
The effects of intermittent fasting last for a year
Researchers investigated the popular 16:8 approach to intermittent fasting. In this method, people fast for 16 hours each day and eat during the remaining eight hours.
The lasting effects did not depend on whether participants ate earlier or later in the day. The early schedule allowed eating from 9 a.m. to 5 p.m., while the late schedule used the time from 1 p.m. to 9 p.m.
One year after the end of the intervention, both the early and late fasting groups maintained significantly more weight loss than participants who continued eating for more than 12 hours each day. Significant reductions in fat mass were also maintained in the group assigned to the earlier schedule.
The results of this study suggest that while time-restricted eating is practical in the short term, it can produce lasting effects far beyond the initial program.
Weight and body composition tracking
This research clinical nutritionOfficial Journal of the European Society of Clinical Nutrition and Metabolism. The study involved scientists from the University of Granada (UGR), the Granada Biomedical Research Institute (ibs.GRANADA), the Public University of Navarra, and the Center for Biomedical Research Networking (CIBER).
During the first 12 weeks, all 99 participants received education about the Mediterranean diet. They were then divided into four groups.
The control group continued to eat for at least 12 hours per day. The early fasting group used an 8-hour window starting before 10 a.m. The late fasting group used an 8-hour window starting after 1 p.m. Participants in the self-selection group chose their own 8-hour schedule.
The researchers measured body weight, fat mass, and fat-free mass before and after the intervention. They reassessed the same measurements one year after the program ended.
This study is part of a broader research project, the main findings of which are: natural medicine. These results showed that regardless of when the eating window occurred, participants who practiced TRE lost an average of 3 to 4 kilograms more than participants who only received nutritional guidance.
Weight change remained after the program
Dr. Alba Camacho Cardeñosa, a researcher at the Interuniversity Institute of Sports and Health (iMUDS) of the University of Granada (UGR) and an ibs.GRANADA postdoctoral researcher in the Endocrinology and Nutrition Department of the San Cecilio University Clinical Hospital, is the first author of the study.
She explains, “Until now, we knew that intermittent fasting promoted modest weight loss in the short term, but it was unclear whether the effects were sustained over the long term. By evaluating participants 12 months after the end of the intervention, we demonstrated that weight changes were sustained.”
The researchers also point to evidence that this routine may be manageable outside of controlled studies. They highlight that “a very encouraging finding was that one in three people decided to continue practicing intermittent fasting on their own during that one-year follow-up, suggesting that this is a habit that can be incorporated into daily life relatively easily.”
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 Jonathan Lewis Lewis leads the group.
The project also involved collaborators from the San Cecilio University Hospital, the Virgen de las Nieves University Hospital of Granada, the Public University of Navarra, CIBER on Obesity (CIBEROBN), and CIBER on Frailty and Healthy Aging (CIBERFES).
The researchers say that even 12 weeks of intermittent fasting may be an effective medium-term option for weight management in overweight or obese adults.
Because both early and late mealtime windows provided lasting benefits, patients may be able to choose the schedule that is most comfortable for their routine. This flexibility may make the approach easier and improve its utility in obesity treatment.
Research on metabolic and cardiovascular health
ibs.GRANADA’s MP20 group “Biomarkers of Metabolic and Bone Diseases” investigates biological markers and potential therapeutic targets related to metabolic, bone, and cardiovascular conditions.
The group combines bioinformatics and clinical research to create diagnostic tools and evaluate possible treatments. That research includes investigating intermittent fasting as a treatment for obesity and related health problems, as well as studying whether bone markers can help predict cardiovascular risk.
The group aims to produce research with practical clinical applications through a multidisciplinary and collaborative approach.
