Fasting like Mark Wahlberg and Chris Hemsworth may have multiple health benefits, scientists say — but only if you do it for at least three days straight.
New findings reveal that prolonged fasting sheds unhealthy fat — with the weight staying off — and gives multiple organs, including the brain, a ‘significant’ boost.
But researchers at Queen Mary University in London found the benefits only kick in after at least 72 hours without food.
It means Wahlberg and Hemsworth — who both aim not to eat from 6pm to 11.55am when intermittent fasting — may not be benefitting from the daily 18-hour famine.
Mark Wahlberg, 52, is famous for regularly following the 18:6 intermittent fasting plan, where he doesn’t eat for 18 hours a day (Pictured above in 2019 in Bridgetown, Barbados)
Chris Hemsworth has also previously followed intermittent fasting plans. (He is shown above in 2016 in Byron Bay, Australia)
Many celebrities have also touted the benefits of intermittent fasting, including Hugh Jackman, Halle Berry and Kourtney Kardashian.
Professor Claudia Langenberg said: ‘Fasting, when done safely, is an effective weight loss intervention. Popular diets that incorporate fasting claim to have health benefits beyond weight loss.
‘Our results provide evidence for the health benefits of fasting beyond weight loss, but these were only visible after three days of total caloric restriction — later than we previously thought.
‘For the first time, we’re able to see what’s happening on a molecular level across the body when we fast.’
The study found that protein levels in several organs change after about three days of fasting, indicating that the whole body is responding to the fast.
These proteins, including ones that make up the supportive structure for neurons in the brain, help organs operate more effectively.
The body also changes its source and type of energy, switching from glucose calories that come from food to its own fat stores.
The study’s test subjects, who fasted for seven days straight, lost an average of 12.5lbs. The weight stayed off even three days after fasting ended.
The paper involved 12 volunteers — five women and seven men — who were in their 20s and 30s and weighed 171lbs on average at the start of the study.
Scientists sampled blood every morning and evening during the seven-day fast and for a week afterward and two days beforehand.
Fat mass had dropped by 5lbs by the end of the seven-day fast and then stayed at this level a week later.
Muscle mass had fallen by 7lbs by the end of the fast, but then rebounded by 5lbs in the week that followed. There were also shifts in other measures such as bone mass.
Fasting is practiced by millions of people throughout the world for different medical and cultural purposes, including health benefits and weight loss.
This study suggests that to get the full benefits of fasting, someone may need to go without food for 72 hours – instead relying on only water
Historically, fasting was used to treat diseases such as epilepsy and rheumatoid arthritis. The researchers said the protein changes may explain why it had a positive effect on these and other conditions.
They hope their findings lead to new treatments for people who cannot undergo prolonged fasting.
Dr Maik Pietzner said: ‘While fasting may be beneficial for treating some conditions, often fasting won’t be an option to patients suffering from ill health. We hope these findings can be used to develop treatments that patients are able to use.’
