According to new research from the University of Adelaide, people who repeatedly lose weight only to gain it back may find intermittent fasting easier to maintain than traditional calorie counting.
The study examined not only how much weight people lost, but also how different dietary approaches affected eating habits, mood, sleep and overall quality of life.
The researchers found that intermittent fasting and continuous calorie restriction produced similar weight loss. However, participants who followed the fasting plan did not feel like they had to constantly monitor their eating, avoid overeating, or count calories to achieve those results.
Different mental approach to weight loss
That experience was different from that of people on a calorie-restricted diet. Those participants reported that losing weight required an ongoing effort to consciously limit how much they ate and resist overeating. The researchers estimated that this greater sense of control accounted for about 15% of their weight loss.
“While many diets can result in weight loss, they can be difficult to follow and this makes maintaining that weight long-term more challenging,” said Professor Leonie Heilbronn from the University of Adelaide School of Medicine and the South Australian Health and Medical Research Institute.
“The results of our study indicate that intermittent fasting could offer an alternative avenue for people who find the conventional diet challenging.”
How the study compared three diet plans
More than 200 adults with obesity participated in the 18-month clinical trial. Participants were randomly assigned to one of three groups: intermittent fasting, continuous calorie restriction, or standard care.
Those in the intermittent fasting group consumed 30% of their daily energy needs between 8 am and 12 pm on three non-consecutive days each week. After that eating window, they completed a 20-hour fast. The rest of the days they ate their usual diet.
Participants assigned to continuous calorie restriction consumed approximately 70% of their normal caloric intake each day. The standard care group continued their usual diets but received healthy eating guidelines.
Similar weight loss, different experience
After six months, participants in both the intermittent fasting and calorie restriction groups had lost an average of around seven kilograms. In comparison, those who received standard care lost only about two kilograms.
People in both diet groups also reported improvements in depression and general well-being, even on fasting days.
The findings, published in the journal Clinical Nutritionsuggest that intermittent fasting and caloric restriction may promote weight loss through different psychological and behavioral mechanisms.
“Psychological and behavioral effects have an important influence on people’s ability to follow diets. Intermittent fasting can help people lose weight in ways that are less dependent on conscious restriction of intake,” said Professor Heilbronn.
Why researchers want to study intermittent fasting further
Although intermittent fasting has rapidly gained popularity, researchers say much is still unknown about its long-term psychological and behavioral effects compared to more traditional diet strategies.
“Future trials should be designed to identify people struggling to improve their eating behaviors as they may do better on intermittent fasting diets, allowing for more personalized weight management,” Professor Heilbronn said.