Fasting every second day may be secret to weight loss
Fasting every other day could be the secret to losing weight while staying healthy because it mimics humans’ caveman diet, a new study suggests.
A trial showed that people who ate no food at all for 36 hours, followed by anything they felt like for 12 hours, lost about 3.5kg in a month.
Crucially, their immune systems remained stable, even after six months, in contrast with many diets that aim to restrict calorie intake each day.
Scientists at the University of Graz in Austria believe the strength of alternate-day fasting (ADF) may lie in its adherence to hunter-gatherers’ patterns of eating thousands of years ago, when food was not available every day.
However, they warn it may not be suitable for everyone and further studies are needed.
Published in the journal Cell Metabolism, the study recruited 60 participants who were enrolled into either an ADF group or a control group where they were allowed to eat whatever they wanted.
The ADF group members were required to fill in food diaries and also underwent continuous glucose monitoring to ensure they stuck to the routine. The scientists found that, on average, the dieters ate normally during the 12 hours they were at liberty to eat an unlimited amount.
Overall, they reached an average calorie restriction of around 35% and lost an average of 3.5kg after four weeks.
“Why exactly calorie restriction and fasting induce so many beneficial effects is not fully clear yet,” University of Graz head of endocrinology Professor Thomas Pieber said.
“The elegant thing about strict ADF is that it doesn’t require participants to count their meals and calories: they just don’t eat anything for one day,” he said.
Professor Frank Madeo, his colleague, said: “The reason might be due to evolutionary biology.
“Our physiology is familiar with periods of starvation followed by food excesses.”
A further 30 participants were put on ADF for six months, to assess the safety of the diet over a longer period, with positive results.
They had a reduction in belly fat, which has been linked to a higher risk of cancer
Previous studies had suggested that consistent calorierestrictive diets can result in malnutrition and a decrease in immune function.
In contrast, even after six months of ADF, the participants’ immune function appeared to be stable.
They had a reduction in belly fat, which has increasingly been linked to a higher risk of cancer.
The group also showed lower levels of triiodothyronine, a hormone that has been associated with longer lifespans in previous research.
The new study is likely to shift the continuing debate in favour of intermittent rather than consistent dieting.
Many people say they find consistent calorie restriction difficult to sustain and often succumb to “yo-yo” eating.- The Telegraph