Intermittent fasting, a widely popular eating pattern advocated by many for weight loss and other health benefits, has been the focus of a recent large-scale trial.
Researchers from King's College London found that restricting eating to a 10-hour window during the day reduces hunger and improves mood and energy. The results of the trial were presented at the European Nutrition Conference in Belgrade.
Intermittent fasting involves alternating periods of fasting and eating, which can be done in many ways. One popular method is time-restricted eating (16/8 or 14/10), wherein daily intake of food is limited for a certain window of time, and fasting during the remaining hours. The 16/8 method is when a person fasts for 16 hours and eats during an 8-hour window, while the 14/10 method is when a person fasts for 14 hours and eats during a 10-hour window. Other methods are alternate-day fasting, twice-a-week fasting and 24-hour fasting once a week.
Researchers conducted the trial on 37,545 participants who use a ZOE health app. During the three-week trial, the participants were asked to eat normally for the first week, and then limit eating to a 10-hour window in the next two weeks.
After the trial period, 36,231 participants opted for additional weeks. Of the total participants, 27,371 users were classified as highly engaged and 78% of them were female.
The researchers observed greater benefits in those who had a longer eating window even before the trial.
"This is the largest study outside of a tightly controlled clinic to show that intermittent fasting can improve your health in a real-world setting. What's really exciting is that the findings show that you don't have to be very restrictive to see positive results: a ten-hour eating window, which was manageable for most people, and improved mood, energy levels, and hunger," Dr. Sarah Berry, a study author, said in a news release.
People who were consistent with their eating window had greater benefits, compared to those who changed them daily.
"We found for the first time that those who practiced time-restricted eating but were not consistent day to day, did not have the same positive health effects as those who were dedicated every day," Berry said.
"This study adds to the growing body of evidence showing the importance of how you eat. The health impact of food is not just what you eat but the time at which you choose to consume your meals, and the eating window is an important dietary behavior that can be beneficial for health. Findings show that we don't need to be eating all the time. Many people will feel satiated and even lose weight if they restrict their food to a ten-hour window," Kate Bermingham, another researcher said.
