Intermittent Fasting: A Trending Weight Loss Method or Just a Fad?
Intermittent fasting has made a comeback in recent months, garnering attention from famous personalities and the release of books on the subject. Advocates of intermittent fasting claim that it not only aids in rapid weight loss but also improves overall health and well-being. Former Prime Minister Matteo Renzi recently credited intermittent fasting for his six-kilogram weight loss, joining the long list of individuals who have attested to its effectiveness. This resurgence in popularity can be traced back to statements made by Antonella Viola, a professor at the University of Padua, known for her expertise on the coronavirus pandemic.
Intermittent fasting is often hailed as an easier alternative to traditional diets, as it requires fewer sacrifices. Those who practice it often bypass consulting with a nutritionist, assuming that a few simple rules are all that is needed to shed pounds. However, this approach can be risky, especially for individuals with specific health conditions related to their metabolism that they may not be fully aware of.
The concept of fasting itself is not complicated – it involves abstaining from food and, in some cases, liquids for a certain period. Fasting has been practiced for cultural, religious, and even health-related reasons throughout history. Ancient Greeks fasted before consulting the oracles, while fasting in various African tribal cultures was a means of communicating with spirits. Fasting is also seen as a path to mystical experiences in Buddhism. Religions worldwide incorporate fasting as a means of spiritual reflection, such as during Ramadan for Muslims. Additionally, hunger strikes, a form of protest, involve prolonged fasting.
Weight loss is an inevitable result of prolonged fasting, as the body starts utilizing stored fat and proteins in the absence of food. Based on this concept, researchers in the early 20th century began exploring whether intermittent fasting, with shorter fasting periods, could be an effective treatment for obesity. Initial studies were limited and inconclusive. However, more comprehensive and structured research emerged in the 1960s.
The documented experiences involved fasting periods ranging from one day to a couple of weeks, depending on the case. Although there were enthusiastic articles on intermittent fasting, there was insufficient evidence to determine its efficacy and safety. Conducting studies on diets is challenging due to individual variations in response and the need for long-term monitoring of participants to gauge effectiveness. As a result, even after almost a century, there are still no definitive findings on the benefits of intermittent fasting, similar to many other diet types.
Intermittent fasting encompasses multiple variations, with individuals customizing their eating habits to suit their preferences, sometimes resulting in potential health risks. Two broad categories can be identified – periodic fasting and time-restricted feeding. Periodic fasting involves alternating fasting or restricting caloric intake on specific days with normal eating on others. Time-restricted feeding, on the other hand, restricts eating to specific hours of the day.
Numerous diets fall within these categories, combining fasting phases with regular nutrition. Daily fasting involves alternating fasting and eating days, the 5:2 diet allows for two days of fasting and five days of normal eating, and mimicking fasting recommends gradually reducing caloric intake while primarily consuming vegetables over five days. Another approach involves an eating window of 8-10 hours, followed by a fasting period of 14-16 hours. The latter is popular due to the ease of skipping a meal and utilizing sleep time, which already involves fasting.
Advocates of intermittent fasting often cite studies conducted on rodents, claiming that alternate day feeding keeps these animals leaner and healthier. While the reasons behind these outcomes are not fully understood, it is hypothesized that the body intensifies the use of glycogen and fat reserves in the absence of nutrients. However, replicating these conditions and their effects in humans is challenging, resulting in a lack of conclusive evidence supporting the superiority, safety, and health benefits of intermittent fasting compared to traditional diets.
A recent study divided 139 obese individuals into two groups, subjecting them to either a classic calorie-restricted diet or an intermittent fasting diet with an eating window between 8 a.m. and 4 p.m. Both groups aimed for a daily caloric intake of 1500-1800 kilocalories for men and 1200-1500 kilocalories for women. After a year-long trial, the research team observed similar weight loss, reduction in body fat, blood pressure, and blood glucose levels in both groups. Therefore, they concluded that there were no significant differences between the two approaches, suggesting that intermittent fasting does not provide superior weight loss outcomes compared to a regular diet.
Various factors suggest that the effectiveness of intermittent fasting lies in the reduction of daily calorie intake rather than the timing of meals. Individuals who claim success with intermittent fasting often attribute it to significant changes in eating habits that extend beyond fasting periods. For example, Renzi mentioned resuming regular running, while Viola attributed her weight loss to eliminating alcohol consumption. These lifestyle changes play a crucial role in weight management, alongside intermittent fasting.
One advantage of intermittent fasting is the adherence to a strict schedule, reducing the chances of overeating, making exceptions, or succumbing to temptations. However, it is essential to remember that significant weight loss is only achievable by consuming fewer calories than one’s usual intake. While intermittent fasting may aid in calorie reduction, its effectiveness must be considered alongside overall dietary habits and lifestyle changes for sustainable results.