Going to sleep without dinner, a valid strategy to lose weight?

In a recent study, a group of volunteers have been thoroughly examined what effect not eating anything for a longer period of hours daily than usual has in combating overweight, obesity and their associated problems, including, among other possibilities, not Eat nothing between five in the afternoon and nine in the morning the next day.

In Spain, the prevalence of overweight and obesity reaches 70% in men and 50% in women, which is associated with multiple metabolic alterations such as type 2 diabetes and exponentially increases the risk of developing cardiovascular diseases, hypertension and certain types of cancer. . In other countries, the situation is comparable. This alarming increase in weight in the population not only reduces people’s quality of life, but also represents a great challenge for the public health system. The scientific community is working intensely to find and implement effective, but at the same time simple, strategies to treat this problem that is already considered a disease.

Calorie restriction diets help you lose weight and improve cardiovascular health. However, they are not easy to maintain in the long term and tend to lead most people to end up abandoning the treatment and therefore regain the lost weight, and even gain more weight than they started with.

Given the difficulties of maintaining adherence to traditional calorie restriction, new nutritional strategies emerge. One of them is intermittent fasting, which consists of alternating periods of eating with periods of fasting that range from hours to days. One type of intermittent fasting that has gained popularity in recent years is one that reduces the number of hours you can eat and extends the hours you fast each day. It is known as time-restricted eating. Normally, in Spain, people have their first breakfast at 7-8 in the morning and dinner at 9-10 p.m., therefore, they have an intake window of 12-14 hours. In this type of intermittent fasting, the intake window is reduced from 12-14 hours to 6-8 hours, and you fast for 16-18 hours. This nutritional strategy helps maintain a daily cycle of intake and fasting, which stabilizes the biological rhythms of our body. We know that eating irregularly or at night alters these rhythms and increases the risk of obesity, cardiovascular diseases and type 2 diabetes.

The PROFITH CTS-977 research group of the Department of Physical and Sports Education, at the Faculty of Sports Sciences and Joint University Institute of Sports and Health of the University of Granada (UGR), led by Dr. Jonatan Ruiz, in collaboration with the Biosanitary Research Institute of Granada, the San Cecilio Clinical University Hospital and the Virgen de las Nieves University Hospital of Granada, as well as the research group led by Dr. Idoia Labayen of the Public University of Navarra and the University Hospital of Navarra, together with the Network Biomedical Research Center for the Physiopathology of Obesity and Nutrition (CIBEROBN) and the Network Biomedical Research Center for Frailty and Healthy Aging (CIBERFES), In Spain, all these entities, has investigated the effects of a 12-week intervention with three different fasting strategies: early fasting (intake window: approximately 9:00-17:00), late fasting (approximately 14:00-22:00), and self-selected fasting, where people could select the time slot in which they wanted to eat, and they did so on average between 12:00 p.m. morning and 8 p.m.

Jonatan Ruiz, co-author of the study. (Photo: UGR)

In addition, all people participating in the study also received standard treatment, which consisted of a nutritional education program on the Mediterranean diet and healthy lifestyles. In this multicenter randomized controlled trial, carried out in Granada (southern Spain) and Pamplona (northern Spain) and one of the largest carried out to date, a total of 197 people (50% women) participated among 30 and 60 years old. 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, who is currently carrying out his postdoctoral studies at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of 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 indicate that it is not clear whether the timing of the intake window—early , delayed or self-selected—may have a different effect on weight loss, visceral fat (that is, the fat that surrounds the organs in the abdominal area), or cardiovascular health in generally in people who are overweight or obese.

The results of the study reveal that intermittent fasting did not show additional benefits to a nutritional education program in reducing visceral fat. However, the fasting groups, regardless of the time of intake, achieved greater weight loss, on average 3-4 kg, compared to the usual treatment group that continued with its intake window of at least 12 hours. . It is noteworthy that the early fasting group reduced abdominal subcutaneous fat to a greater extent, that is, the fat we have just under the skin.

The study also assessed fasting glucose levels and 24-hour glucose 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 glucose levels and overnight glucose compared to the rest of the groups.

These findings suggest that early fasting could be especially beneficial for optimizing glucose regulation, which could help prevent diabetes and improve metabolic health. By not eating at night, you allow the body more time to digest and process nutrients, thereby facilitating better regulation of blood glucose, thereby reducing the risk of developing sugar problems and other metabolic disorders, such as as indicated by Dr. Labayen, principal investigator of the study in Pamplona and member of CIBEROBN together with Dr. Jonatan Ruiz and Dr. Manuel Muñoz (CIBERFES).

The researchers highlight that all fasting groups had a high adherence 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.

The study is titled “Effects of early, late and self-selected time-restricted eating on visceral adipose tissue and cardiometabolic health in participants with overweight or obesity: a randomized controlled trial.” And it has been published in the academic journal Nature Medicine. (Source: UGR)