New study finds early fasting melts belly fat

Intermittent fasting is an effective method for weight loss and improves cardiovascular health in obese people.

A research team led by the University of Granada (UGR), the Public University of Navarra (UPNA) and CIBER has demonstrated that intermittent fasting, that is, limiting meal times and extending periods daily fasting, is an effective strategy for losing weight and improving the cardiovascular system. health of obese people.

Published in the renowned journal Nature Medicine, the study shows that finishing the last meal before 5 p.m. and skipping dinner is a safe and effective approach to reducing subcutaneous abdominal fat, the layer of fat beneath the skin. This method is particularly beneficial after periods of overeating, such as during the holiday season.

In Spain, overweight and obesity affect 70% of men and 50% of women. These pathologies are closely linked to metabolic disorders such as type 2 diabetes and considerably increase the risk of cardiovascular diseases, hypertension and certain cancers. This widespread weight gain not only reduces quality of life, but also constitutes a heavy burden on the public health system. Ongoing scientific research aims to develop effective and practical strategies to address this growing health crisis, now officially recognized as a disease.

Low-calorie diets help lose weight and improve cardiovascular health. However, they are not easy to maintain over the long term and often lead most people to abandon treatment and thus regain the lost weight, or even gain more than their starting weight.

Faced with the difficulties of maintaining compliance with traditional calorie restrictions, new nutritional strategies are emerging. One of them is intermittent fasting, which involves alternating periods of eating with periods of fasting ranging from a few hours to several days. One type of intermittent fasting that has gained popularity in recent years is one that reduces the number of hours you eat and extends the hours you fast each day. This is what we call limited time eating.

Normally in Spain people have their first breakfast at 7:00 a.m. and their dinner at 9:00 p.m. and 10:00 p.m., so they have a 12-14 hour eating window. In this type of intermittent fasting, the intake window is reduced from 12 to 14 hours to 6 to 8 hours, and people fast for 16 to 18 hours. This nutritional strategy allows us to maintain a daily cycle of eating and fasting, which stabilizes the biological rhythms of our body. We know that eating irregularly or at night disrupts these rhythms and increases the risk of obesity,

” data-gt-translate-attributes=”({“attribute=”” tabindex=”0″ role=”link”>cardiovascular diseaseand type 2 diabetes.

The PROFITH CTS-977 research group of the Department of Physical and Sports Education, Faculty of Sports Sciences and the University Institute for Research on Sport and Health (iMUDS) led by Dr. Jonatan Ruiz, in collaboration with ibs .Granada, the University Hospital Clínico San Cecilio and the Virgen de las Nieves University Hospital of Granada, as well as the research group led by Dr. Idoia Labayen of the University of Granada, in collaboration with Dr. Idoia Labayen of the University of Granada and the Virgen de las Nieves University Hospital of Granada. Idoia Labayen of the Public University of Navarra and the University Hospital of Navarra, in collaboration with CIBER on Obesity (CIBEROBN) and CIBER on Frailty and Healthy Aging (CIBERFES), studied the effects of a 12-week intervention with three different fasting strategies. : early fasting (admission sale: approximately 9:00 a.m. to 5:00 p.m.), late fasting (approximately 2:00 p.m. to 10:00 p.m.), and self-selected fasting, where people could select the time slot during which they wanted to eat, on average between midnight and 8 p.m.

Study with 197 participants

Additionally, all people participating in the study also received the standard treatment, which consisted of a nutritional education program on the Mediterranean diet and healthy lifestyles. In this randomized, controlled, multicenter trial, conducted in Granada (southern Spain) and Pamplona (northern Spain) and one of the largest to date, a total of 197 people (50% women ) aged 30 to 60 years participated. Participants were randomly assigned to one of the following groups: treatment as usual (49 participants), early fasting (49 participants), late fasting (52 participants), or self-selected fasting (47 participants).

This study was part of the doctoral thesis of Manuel Dote-Montero, currently a postdoctoral researcher at the prestigious National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) in the United States.

Manuel Dote-Montero, together with Antonio Clavero Jimeno, predoctoral researcher at the UGR, and Elisa Merchán Ramírez, postdoctoral researcher at the UGR, led this study in Granada and indicates that it is not clear whether the timing of the intake window – early, late or voluntary – may have a different effect on weight loss, visceral fat (i.e. fat surrounding the organs in the area abdominal) or overall cardiovascular health in overweight or obese people.

The results of the study, published in the prestigious journal Natural medicinereveal that intermittent fasting showed no additional benefit over a nutrition education program in reducing visceral fat. However, the fasting groups, regardless of the timing of intake, achieved greater weight loss, on average 3 to 4 kg, compared to the usual treatment group who continued their fasting window. least 12 hours. Notably, the first fasting group reduced abdominal subcutaneous fat, that is, the fat just under the skin, to a greater extent.

The study also assessed fasting and 24-hour glucose levels using a continuous glucose monitor worn by participants for 14 days before and at the end of the intervention. The results show that the early fasting group significantly improved fasting blood sugar levels and overnight blood sugar levels compared to the other groups.

Regulate glucose

These results suggest that early fasting may be particularly beneficial for optimizing glucose regulation, which could help prevent diabetes and improve metabolic health. Not eating at night gives the body more time to digest and process nutrients, better blood sugar regulation is facilitated, thereby reducing the risk of developing sugar problems and other metabolic disorders, explains researcher Dr. Labayen principal of the study in Pamplona and member of CIBEROBN with Dr. Jonatan Ruiz and Dr. Manuel Muñoz (CIBERFES).

The researchers point out that all fasting groups had a high compliance rate and no serious adverse events were recorded. Intermittent fasting is therefore presented as a safe and promising strategy for managing body weight and improving cardiovascular health in overweight or obese people. This information could be crucial to improve the effectiveness of nutritional interventions in these populations.

Reference: “Effects of early, late, and time-restricted feeding on visceral adipose tissue and cardiometabolic health in overweight or obese participants: a randomized controlled trial” by Manuel Dote-Montero, Antonio Clavero-Jimeno, Elisa Merchan-Ramírez, Maddi Oses, Jon Echarte, Alba Camacho-Cardenosa, Mara Concepción, Francisco J. Amaro-Gahete, Juan MA Alcántara, Alejandro López-Vázquez, Rocío Cupeiro, Jairo H. Migueles, Alejandro De-la-O, Patricia V. García Pérez, Victoria Contreras-Bolivar, Araceli Muñoz-Garach, Ana Zugasti, Estrella Petrina, Natalia Alvarez de Eulate, Elena Goñi, Cristina Armendariz-Brugos, Maria T. González Cejudo, José L. Martín-Rodríguez, Fernando Idoate, Rafael Cabeza, Almudena Carneiro-Barrera, Rafael de Cabo, Manuel Muñoz-Torres, Idoia Labayen and Jonatan R. Ruiz, January 7, 2025, Natural medicine.
DOI: 10.1038/s41591-024-03375-y