Lose weight through fasting every day?
How effective is Intervallfast, where people only eat four or six hours a day? The results of a new study show that this type of food intake helps people to consume about 550 fewer calories each day, which is associated with significant weight loss in the long term.
The current study by the University of Illinois at Chicago looked at how daily fasting affects weight. The results were published in the English language journal "Cell Metabolism".
Participants were only allowed to eat four or six hours a day
The study examined the effects of two different forms of interval fasting on weight. In one form, the participants were only allowed to eat food in a period of four hours, in the second this period was six hours. The effects of fasting in both groups were compared to a non-fasting control group.
The research is the first human clinical trial to compare the effects of two popular forms of interval fasting on body weight and cardiometabolic risk factors, the researchers report.
How was the investigation structured?
The participants in the group with the 4-hour food intake were asked to eat only between 1:00 p.m. and 5:00 p.m. The participants in the other group were asked to eat only between 1 p.m. and 7 p.m. Both groups were allowed to eat whatever they wanted during their food intake.
What were the participants allowed to eat during Lent?
During daily Lent, the participants were only allowed to drink water or drinks without calories. However, people in the control group should try to maintain their weight and not change their diet or physical activity level.
What was measured
All participants were monitored for a period of ten weeks, whereby weight, insulin resistance, oxidative stress, blood pressure, LDL cholesterol, HDL cholesterol, triglycerides and inflammation markers were measured.
Effects of fasting
The researchers found that simply adhering to the schedule in both fasting groups reduced caloric intake by approximately 550 calories a day and lost about three percent of their body weight over the period of the study. In addition, insulin resistance and oxidative stress decreased in these individuals compared to control panelists.
Are there any other differences between the groups?
No effects on blood pressure, LDL cholesterol, HDL cholesterol or triglycerides were found. The researchers also observed no significant difference in weight loss or cardiometabolic risk factors between the two fasting groups.
Fasting diets are suitable for weight loss
"The results of this study are promising and confirm what we have seen in other studies - fasting diets are a viable option for people who want to lose weight, especially for people who do not want to count calories or find other diets tiring," says study author Professor Krista Varady of the University of Illinois at Chicago in a press release.
Which period of fasting makes the most sense?
"It is also significant that there was no added weight loss benefit to those who have been fasting for longer," added the expert. Until further studies are available that compare the two diets directly or examine the optimal time for fasting, the restriction to a 6-hour daily food intake during interval fasting can be considered sufficient. (as)
Author and source information
This text corresponds to the specifications of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
- Sofia Cienfuegos, Kelsey Gabel, Faiza Kalam, Mark Ezpeleta, Eric Wiseman et al .: Effects of 4- and 6-h Time-Restricted Feeding on Weight and Cardiometabolic Health: A Randomized Controlled Trial in Adults with Obesity, in Cell Metabolism (published 07/15/2020), Cell Metabolism
- University of Illinois at Chicago: How long should you fast for weight loss? (published July 15, 2020), University of Illinois at Chicago