Intermittent fasting shows promise in managing obesity and cardiovascular health

A team of scientists led by the University of Granada (UGR), the Public University of Navarra (UPNA) and CIBER has shown that intermittent fasting (reducing the number of hours of intake and extending the hours of fasting each day ) is an effective way. method for losing weight and improves the cardiovascular health of people suffering from obesity problems.

Their work, published in the prestigious journal Natural medicinereveals that eating the last meal before 5 p.m. and then skipping dinner in the evening is a safe and effective strategy for reducing subcutaneous abdominal fat, that is, the fat just under the skin, especially after periods of excess like Christmas.

In Spain, the prevalence of overweight and obesity reaches 70% in men and 50% in women, which is associated with multiple metabolic disorders such as type 2 diabetes and exponentially increases the risk of developing cardiovascular disease, hypertension and certain types of cancer. This alarming weight gain in the population not only has an impact on people’s quality of life, but also represents a major challenge for the public health system. Scientific research is working hard to implement effective yet simple strategies to treat this problem, now considered 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 weight lost, 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, cardiovascular disease and 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 UGR, and Elisa Merchán Ramírez, postdoctoral researcher at UGR, led this study in Granada and indicates that it is not clear whether the timing of the intake window – early, late or self-selected – may have a different effect on weight loss, visceral fat (i.e. fat surrounding the organs of the abdominal region) or overall cardiovascular health in overweight or obese people.

The study results, published in the prestigious journal Nature Medicine, reveal that intermittent fasting showed no additional benefit over a nutrition education program for 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 for these populations.