Unlike other fad diets like the grapefruit diet, cabbage soup diet, juice cleanses and more, Intermittent fasting (IF) has maintained its relevance over the years. Although the concept has been around for some time, it gained widespread popularity in 2012 after the BBC documentary Eat, Fast, and Live Longer. In it, British journalist Michael Mosley followed a regimen of normal eating for five days, with a drastic reduction in intake on two days, often limiting himself to just breakfast. Within five weeks, Mosley lost over 14 pounds and saw significant improvements in his cholesterol and blood sugar levels. This documentary, along with the bestselling book that followed, catapulted IF into the spotlight as a leading diet trend.
Recent studies continue to confirm the metabolic benefits of intermittent fasting. Also known as time-restricted eating, IF usually involves an eight-hour eating window, with only clear liquids consumed during the remaining 16 hours. New research published in JAMA Network Open underscores the significant metabolic advantages of IF, further solidifying its place in modern-day health discourse.
The 16-hour fasting theory, in particular, has been discussed extensively as a beneficial practice for overall health. We know that it has several benefits for the body—and we are not just talking about losing weight, as experts insist that this should not be the main objective when doing it. As explained by Jorge Herranz, a nutrition expert. “After those magic 12 or 16 hours without eating during the night—the body activates autophagitation or, in other words, a cell regeneration process that reduces the risk of suffering certain diseases, regulates emotional tension and cognitive capacity and teaches the body to use fat as fuel.”
Before deciding to put this nocturnal fasting into practice myself, I consulted a nutritionist beforehand to assess all my doubts—how to do it and how to adapt it to my daily life. Here's what I found.
What is autophagy?
Promoting autophagy is, without a doubt, the greatest benefit of fasting and the one most experts insist on. Sandra Lordén Álvarez, an expert in sports nutrition, explains it as follows: "Autophagy is a natural process that aims to regenerate the body from the inside, as a cellular recycling process, which helps to fight aging, eliminate toxins and/or prevent diseases by promoting DNA activity," she explains. And although this is undoubtedly the advantage on which all experts agree, Lordén Álvarezez also refers to other data. "Some studies suggest that fasting increases insulin and growth hormone sensitivity. And both are related to greater weight loss". Although we insist, even if it is a collateral benefit, it is not the reason why fasting should be done.
The early benefits of 16-hour fasting
I won't say that it's easy to go a significant part of the morning without eating anything and even more so when my day starts quite early but the reality is that it's a matter of time to get used to it and start differentiating what is emotional hunger, which happens when you start this type of fasting- and real hunger. It is true that after 3 days you begin to naturalize this change of habits and eating food during the 8 central hours of the day, without nighttime snacking while watching a Netflix series, is assimilated as something natural and necessary. Especially when you experience two of the most immediate benefits of intermittent fasting: better quality of sleep and less body swelling.
Can you exercise first thing in the morning during intermittent fasting?
For me, who does a mini-session of barré 30-minute mini barre session as soon as I get up, I was a little hesitant to go without food until noon. But nutritionist Mireia Cervera, of Flax & Kale-the healthy restaurant group, designed a 16:8 fasting plan to do at home-closes ranks on the subject. "Many people are afraid of suffering from hypoglycemia (low blood sugar levels), but this situation is more likely to occur if we have a coffee with milk and a croissant for breakfast and after two hours we go to the gym. In this case, hypoglycemia may appear, precisely because of what has been eaten, since once it has been digested, it generates a drop in blood sugar. It is this type of food that can generate these energy imbalances. Paradoxically, if we start to move without having eaten, we will notice elevated energy levels, and this is due to increases in the hormone adrenaline. Your body starts to use fat reserves. However, the recommendation is always to introduce fast training progressively, with low-intensity workouts that can be increased little by little.
Can you drink coffee with milk while intermittent fasting?
For coffee drinkers like me, the first coffee in the morning is one of my favourite moments of the day. The eternal doubt is whether it is possible to drink coffee with milk during this type of fasting, especially in the early hours of the morning. As Cervera explains to me, coffee does not break the benefits of fasting. You can also drink it as soon as you wake up during the fasting hours but you should drink it alone. "Coffee does not take you out of the metabolic state in which you find yourself during fasting, but it should be black, American-style (diluted with water), without milk, vegetable drinks or sweeteners," he explains. In the same way, if outside the 8 hours in which you can ingest food, you feel like eating, it is allowed to drink herbal teas, vegetable broths, naturally flavoured waters and water. In fact, “it is important to emphasize that whenever we are doing intermittent fasting we will have to drink more water and make sure we stay hydrated,” he says.
What can you eat during a 16-hour intermittent fast?
Engaging in intermittent fasting doesn’t mean eating less, but rather eating within a concentrated period. Alongside this approach, it's essential to reshape our emotional relationship with food by adopting healthier habits. This includes prioritising nutrient-dense foods such as healthy fats, proteins, tubers, fruits, and vegetables over processed or sugary options. When these foods are consumed in proper proportions, the feeling of genuine hunger is kept at bay.
How much weight can you shed with 16-hour intermittent fasting?
Shifting dinner to an earlier time and delaying breakfast can help in weight management, but this shouldn’t be the primary focus. While weight loss can be one of the effects of intermittent fasting, and numerous studies have shown that eating within an 8-10 hour window can lead to sustained weight loss, fasting shouldn't be viewed solely as a fat-loss solution. According to the experts at Flax & Kale, fasting should be approached as a way to enhance alertness, improve performance, and cultivate a more natural relationship with food. Moreover, it can boost overall health and help normalize weight.
This article first appeared on www.vogue.es
Also read:
What nobody tells you about the intermittent fasting diet
3 reasons why intermittent fasting is better than cutting calories, according to an expert
I tried intermittent fasting for a week, and the results have me sold
