Doctors issue warning over Sharon Osbourne’s three-day fast: Millions of women could be at risk of infertility

Sharon Osbourne this week revealed she goes without eating for 72-hour stretches every week – a dangerous habit that doctors warn carries major health risks.

The 70-year-old TV personality said she doesn’t eat for ‘at least’ three days on the latest episode of The Osbournes Podcast.

Dr Jason Fung, the doctor who invented the intermittent fasting diet, told DailyMail.com the practice could be ‘very dangerous’ if your body doesn’t have enough calories in fat stores.

And Dr Mary Jacobson, chief medical officer at telemedicine company Hello Alpha based in Palo Alto, California, told DailyMail.com: ’72 hours is really, really extreme.’

Someone attempting to fast for this long would feel incredibly lethargic and weak, she said, and would be putting themselves at risk of severe psychological symptoms.

And experts have previously told DailyMail.com that fasting for long periods can impact the hormones that regulate menstruation in women and, in some rare cases, could lead to infertility. 

Ms Osbourne revealed she went three days without eating in a conversation with her son, Jack, about doomsday prepping.

During the conversation, Sharon’s son Jack explained: ‘If you have something that someone wants, they’ll kill you for it. You know how far away we are as a society from complete and utter breakdowns? Nine meals.

‘When you break it down, you are nine meals away from complete and utter breakdown. That’s three days of breakfast, lunch and dinner. That goes away for people, they go three days without eating, they will murder each other, their neighbors, everything.’

Ms Osbourne then replied: ‘God, I do that every week. At least three days without eating.’

‘That’s called intermittent fasting,’ podcast guest star Jason Kennedy replied.   

Research into the health benefits of intermittent fasting – eating within a limited timeframe – has piled up, with the practice’s founders Megan Ramos and Dr Fung extolling its benefits for reversing type 2 diabetes, burning excess body fat, extending a person’s lifespan, staving off heart disease, and even preventing cognitive decline associated with dementia.

Following an intermittent fasting regimen includes switching between days of fasting and days of eating normally. On fasting days, dieters restrict their eating to certain windows throughout the day, such as only eating at breakfast or dinner. 

This can lead to irregular periods, which have been linked to a higher risk of ovarian cancer, heart disease, type 2 diabetes, and mental health problems.

Some women say they’ve stopped having their periods altogether when they fasted for eight to 12 hours per day.

Forcing the body to go without nutrients for long stretches can lead to hormonal deficiencies, as hormones can’t function properly without adequate nutrients.

Without hormones, such as the luteinizing hormone (LH) and follicle-stimulating hormone (FSH), women are more likely to have irregular periods and, in more rare cases, become interfile. This is because without a period, women can’t ovulate, which diminishes their chance of getting pregnant.

‘It’s kind of a cascade of effects on hormones from there,’ Carolyn Williams, a dietitian based in Alabama, previously told DailyMail.com. 

Women who have irregular periods or struggle with infertility should check with their doctor before doing intermittent fasting, she said, ‘because the last thing you want is to disrupt your hormones.’ 

Fasting ‘all depends on your situation,’ Dr Fung told DailyMail.com.

‘If you’re very skinny like [Sharon] looks, certainly I would not recommend it,’ he said.

‘If you’re underweight and not eating for three days, it’s not particularly healthy. That’s sort of just common sense.’

Speaking previously to E! News, Sharon explained: ‘In my life, the heaviest I was, 230 pounds and I’m now under a hundred. And I want to maintain at about 105 because I’m too skinny. But I’m trying to have a healthy balance.’

Dr Fung said: ‘If you’re under 100 pounds, yes, [fasting] is bad.’

Ms Osbourne previously revealed she had lost more than 28 pounds after using the weight-loss drug Ozempic to achieve her new figure.

But she has since stopped using the drug because she said it made her nauseous every day and is not a ‘quick fix’.

She told E! News: ‘But listen, I took it for four months, I lost 30 pounds. I’ve just shoved two chips in my mouth, while we had the break, and I eat normally now, and I haven’t put on a pound. Nothing.’ 

Dr Fung stressed that fasting itself is not bad and is a ‘godsend’ for some people trying to lose weight.

But if there is little to no excess weight to lose, such as in Ms Osbourne’s case, fasting could ‘start to burn or metabolize things you don’t want it to’ like functional muscle and protein, he said.

‘If you don’t have any energy to lose, then you’re going to start really shutting down your metabolism. Your heart rate is going to slow down; your blood pressure is going to drop, your body temperature is going to drop, because your body is now having to conserve calories.’

He added: ‘You’re going to feel tired, you’re going to feel cold, you’re going to feel hungry, you’re not going to feel well. If it continues, then your body is going to have to take those calories by taking functional tissue, which is muscle and other proteins and burn it for fuel… it’s not what you want to do. 

‘You see this with anorexia nervosa. It’s not healthy; people die of those conditions.’

Dr Jacobson said it would not be a good idea for anyone to fast for three days. 

‘Periodic, 72-hour fasting, it’s not sustainable,’ she said. ‘Someone is not going to continue doing that. Then the patient gets into a vicious cycle of what we call weight cycling, or yo-yoing… they may end up gaining more weight than they started out to begin with over time.’

She said there is not much medical research on the effects of a 72-hour fast on the body, but one study found people undergoing the highly restricted diet had an increase in appetite, as well as changes to their mental health. 

Dr Jacobson added: ‘They seemed to mirror major depressive symptoms like sadness, self-blaming, as well as difficulties in decision making. Also loss of libido, for some. Problems that happen at the level of the brain. And this is for people that are healthy.’

Dr Fung said: ‘If you have three days you’re not eating, you need about 5,000 to 6,000 calories to sustain your body. If you have two pounds of body fat, you can certainly do it. So it’s no problem. You’re not going to go crazy because your body has more than enough to spare, two pounds out of the 50 or 60.’

‘If you have 200 or 50 pounds to lose, you can easily afford those three or two pounds.’

But he added: ‘If you don’t have any, then those two pounds are a big deal. You could certainly have psychological consequences. People have gone mad in those situations. There’s mental disease and stuff that happens.’