Singer Ellie Goulding says she fasts for up to forty hours at a time.
The fitness fanatic only has water and other drinks for almost two days, and says it reduces inflammation.
But Ellie, 33, told worried fans the extreme measures had been okayed by a doctor pal, adding: “I do it very safely by having a purposefully nutritious food day the day before and after.
“On the fast day, I drink high-grade electrolytes and a LOT of water (plus tea and coffee). Fasting is safe and beneficial unless you are diabetic or have serious health issues.
“I built my way up to 40-hour fasts over time (started with 12). Fasting from time to is a great way to give your digestive system a break.
“It helps blood sugar control, and helps fight inflammation – the mother of ALL health problems.”
Ellie, living near Oxford during lockdown with husband Caspar Jopling, admitted earlier this year that she had been skipping songwriting and recording sessions to hone her fitness.
She said: “I felt as though I did at one point have a gym addiction that was just not fun, I felt I had to go to the gym every single day.”