Fad dieting risks ruining your chance of being a mum, fertility experts warn

Last month, a picture of my friend, journalist Emma Woolf, appeared on my Twitter feed. It made my heart swell. Looking beamingly happy and relaxed, she was cradling a neat baby bump – she was seven months pregnant, according to the caption.

I was among scores of wellwishers – many of whom, as I did, knew that it had taken Emma, 42, eight arduous years to conceive, during which time there had been setbacks and tragedies. So, of course, I was delighted for her, and relieved. But I’d be lying if I said I didn’t have concerns. 

I was acquainted with Emma’s story long before I actually knew her. Between 2008 and 2014, she appeared on the controversial Channel 4 programme Supersize Vs Superskinny, in which she shed light on the reality of living with the deadliest of all eating disorders: anorexia nervosa.

She later went on to write several highly acclaimed books about her illness, including An Apple A Day, in which she also told of her heart-wrenching desire to be a mother. So powerful was her longing for a child, it ultimately provided the motivation she needed to recover.

Medics are reporting a rise in the number of young women with fertility issues as a result of fad diets

Medics are reporting a rise in the number of young women with fertility issues as a result of fad diets

More recently, she became my friend. We met via my own work, running a website that aims to explode some of the myths that drive unhealthy attitudes to food. We bonded over our shared experiences of eating disorders, which I too suffered five years ago.

When we first speak I tell Emma that I’m unbelievably happy for her but, as diplomatically as possible, that she is still… very thin.

‘I think, if we’re honest, both you and I could do with gaining a few kilograms,’ she replied. ‘But I can genuinely say I am further away from my eating disorder than I’ve ever been.’

And Emma is now quick to highlight that, despite achieving what she’d ‘always dreamed of’, decades of anorexia made getting to this point, at times, traumatic. She and her partner kept trying to conceive, undergoing two rounds of IVF on the NHS, and one privately. 

There were daily jabs of hormones for months on end, twice daily hospital trips and five negative pregnancy tests. ‘It’s not what I signed up for by any means – waiting, wondering, all the injections and hospital appointments,’ she says. ‘Having IVF is like having a full-time job.’

You may think Emma’s struggle is exceptional. After all, only one per cent of the population suffers anorexia. But, though hers is an extreme example, according to a collection of leading experts it doesn’t take a clinical eating disorder to result in similar problems for the reproductive system. In fact, medics are reporting a rise in the number of young women with fertility issues as a result of fad diets.

Such regimes, they say, can cause long-term damage, making conception difficult, sometimes, impossible. They warn of a generation of women risking infertility in a quest to be thin. Renee McGregor, a dietician who specialises in hormonal function and disordered eating, says: ‘A few years back I’d get a couple of referrals a month about missed or stopped periods – now it’s 40 a week.’

Dr Michael Dooley, a former NHS consultant gynaecologist and director of The Poundbury fertility clinic in London, is also seeing an increase in diet-related fertility problems. ‘It’s become a huge problem,’ he says. ‘It doesn’t take much to tip people into these problems – sometimes it’s just a matter of an extra gym class.’

On social media you’ll find a community of women searching for answers to this problem. On Facebook, ‘No Period. Now What?’, set up by biologist and ex-sufferer Nicola Rinaldi, has more than 2,000 members, with 12,000 followers on Instagram. Not all are recovering from eating disorders – some experimented with a new diet, while others started visiting the gym more frequently.

McGregor says: ‘You don’t have to starve for the body to be under-fuelled. Many of my patients have adopted restrictive diets they’ve seen on social media. Others are doing trendy fasting diets while following high-intensity workouts. They can go for years without noticing there’s a problem because they take the Pill and have a withdrawal bleed every month. But when they come off it, the periods don’t come back.’

Emma Woolf, pictured, has lived with the deadliest of all eating disorders, anorexia nervosa, and it took her eight arduous years to conceive, during which time there has been setbacks and tragedies

Emma Woolf, pictured, has lived with the deadliest of all eating disorders, anorexia nervosa, and it took her eight arduous years to conceive, during which time there has been setbacks and tragedies

The absence of periods for more than six months is known medically as hypothalamic amenorrhea or HA – and is estimated to affect between one and three per cent of women aged 17 to 44. I am one of them. I haven’t had a proper period in five years. I’ve written for this newspaper many times about my history of anorexia, which I received treatment for in 2015. 

Today, my relationship with food is peaceful and joyous, and my body mass index, or BMI, is more than healthy. Yet my periods are still missing. Blood tests show my sex hormones – oestrogen, luteinising hormone (LH) and follicle stimulating hormone (FSH) – to be normal. But still, no periods.

How diets play havoc with hormones

Both eating too few calories and having a body fat percentage below roughly 21 per cent can cause the reproductive system to lie dormant, according to specialist dietician Renee McGregor.

The explanation for this lies with the hormone hub at the base of the brain, called the hypothalamus.

‘The hypothalamus keeps our energy balance in check – so if it recognises there’s not enough fuel in the tank, it will shut down some of its processes,’ says McGregor.

‘Coupled with this, a hormone in our fat cells called leptin sends signals to the hypothalamus to instruct the release of a hormone, called gonadotropin-releasing hormone, which keeps the sexual organs working.

‘If there’s not enough body fat, these signals are disrupted.’ Insufficient gonadotropin-releasing hormones causes a cascade of problems for the reproductive system. 

For a start, the development of eggs inside the ovaries is halted.

The hormone that triggers the release of an egg, or ovulation – luteinising hormone – becomes depleted, pausing ovulation, along with the shedding of the lining of the womb.

‘Often the body needs more weight than you might think it needs, following a period of under-nourishment, to ‘decide’ it’s safe to carry a baby,’ explains McGregor. ‘A certain amount of body fat is needed, as well as enough carbohydrate. It only when there’s enough fat and carbohydrate that signals are sent to the brain, firing up the reproductive system.’

Yet my GP sees no problem – there’s no sign that I am unhealthy.

I was told it wasn’t a health condition deemed necessary for specialist treatment, unless I was seeking IVF. This is an issue for many of McGregor’s patients.

‘They’ve often seen three specialists before me who misdiagnose them with polycystic ovary syndrome, which also involves no periods,’ she says. ‘Or doctors say everything is fine and they should come back when they want babies. But it’s not normal, or healthy, not to have a period.’

Dr Dooley agrees. ‘One or two blood tests will provide a snapshot of your hormone function, but doesn’t give the full picture,’ he explains. ‘When you monitor these patients closely over the course of a monthly cycle, you’ll see an irregularity in the release of sex hormones, which is causing the pause in periods and usually ovulation.’

Dr Dooley explains the longer a woman goes without periods, the higher the risk of a reduction in the number of her eggs.

‘Women have a finite number of eggs,’ he says. ‘In patients who’ve had hypothalamic amenorrhea, we see fewer than normal. Occasionally, even when periods have come back and ovulation restarts, there’s a reduction in the number of eggs released for fertilisation.’

But, in the majority of cases, this is temporary – as long as periods return. ‘So far, there’s no evidence that people with a history of hypothalamic amenorrhea who have since regained their menstrual cycle will struggle to conceive,’ he says.

The bigger worry, he says, is what happens during pregnancy.

‘Commonly in these patients, the ovaries may not be releasing enough hormones to sustain a healthy pregnancy,’ he says.

‘And if weight drops again slightly to a BMI below 18.5, which is common, the chance of pre-term hospitalisation increases by ten per cent. There’s also an increased risk of caesarean section, miscarriage and low body weight for the baby.’

Aside from the repercussions for fertility, studies show that HA increases the risk of a host of other health problems – even after periods have returned. One 2002 study published in the Journal of Clinical Endocrinology found that women in their 20s who had severe irregularities in their menstrual cycle were 50 per cent more likely to suffer heart disease in later life.

Dr Michael Dooley, a former NHS consultant gynaecologist and director of The Poundbury fertility clinic in London, is also seeing an increase in diet-related fertility problems

Dr Michael Dooley, a former NHS consultant gynaecologist and director of The Poundbury fertility clinic in London, is also seeing an increase in diet-related fertility problems

A wealth of research links a lack of oestrogen in young adulthood with a rapid acceleration of bone loss, increasing the risk of osteoporosis in later life. One US study found that after just six months of HA, 14 women in their 20s who exercised frequently had the equivalent bone density of a 51-year-old, peri-menopausal woman. Other studies have linked long-term amenorrhea to depression, anxiety disorders and early menopause. ‘The disruption in hormones, caused by having too little energy for too long, has a knock-on effect for countless bodily processes,’ says Renee McGregor.

I’ve written about the topic previously, on my blog, notplantbased.com – and had hundreds of messages from young women in a similar situation. There are famous examples, too. In 2018, Australian Victoria’s Secret model Bridget Malcolm revealed she’d lost her period for seven years as a result of extreme dieting and exercising. Popular fitness bloggers, including British fitness trainer Hayley Madigan, who has more than 200,000 Instagram followers, have admitted the same. But they hide it well.

‘None of my friends are having periods,’ says an actress friend of mine, who struggled to regain regular cycles after a year of ‘clean eating’. ‘When they want to get pregnant, they visit private doctors who prescribe hormone treatment to kick-start their cycles. Or they have IVF.’

Health fact 

By 2100, the average number of children that each woman gives birth to is predicted to fall to 1.7, compared with 4.7 in 1950.

I often wonder how skinny celebrities such as Victoria Beckham remain fertile and Emma Woolf has pondered the same. She says: ‘I was baffled by celebrities having four kids while clearly very underweight. I’d think: how on earth can she do it, when I can’t?’

Beckham, after years of speculation, admitted to ‘disordered eating’ and unhealthy body issues, and to having had a breast augmentation. But if she had been forced, after decades of extreme dieting, to have fertility treatment to conceive, would she ever admit that?

McGregor believes that natural conception for most of the super-slim celebrities plastered over social media would be ‘almost impossible’. ‘Research shows that ovulation occurs only when body fat ratio is above about 21 per cent,’ says McGregor, who has helped elite athletes, who become extremely lean as part of their training, to regain their cycles.

‘Generally speaking, if you can see a woman’s abdominal muscles, their body fat percentage is hovering at about 18 per cent,’ says McGregor. ‘Women won’t be having periods or ovulating with less than 20 per cent body fat – let alone be able to conceive. In fact, most women won’t get periods until they reach a BMI of 20.’

NHS guidance states that women, whether menstruating or not, must have a body mass index (BMI) above 19 before starting fertility treatment. But private doctors may be willing to help those outside of these parameters. Dr Dooley treats a small number of women whose BMI is 18.5 – providing they have nutritional and psychological support, too. ‘We can give a tablet called clomiphene or injections of a hormones called gonadotrophins which stimulates ovulation,’ he says.

While these are ‘highly effective’, Dr Dooley warns of the risks, including cysts on the ovaries and multiple pregnancy.

‘These drugs mustn’t be used before assessing someone’s lifestyle first,’ he says. ‘I also encourage support post-natally, too. Sometimes all it takes is foregoing a weekly gym session and everything kicks back into action. But equally, there are some women who genuinely struggle to gain weight.’

Having written about the rigmarole of fertility treatment, and its associated risks, it is not exactly an attractive option. Firstly, women over 40 are only entitled to one round on the NHS, or three if you’re under 40. If it doesn’t work – which it won’t in a third of cases – you’re looking at paying £3,000 for further attempts at a private clinic. Then there’s the daily injections, which carry risks of infections, agonising headaches, hot flushes and depression. Occasionally, too many eggs develop in the ovaries, causing extreme pain, shortness of breath and fainting. And that’s before you get to the collecting of the eggs – which involves being sedated before a needle is inserted through the vagina.

Emma wishes there had been another way. ‘I want to warn other women that restricting your diet can have serious repercussions,’ she says. ‘Striving for ultra-thinness is simply not worth it, especially if you have dreams of being a mother. Skinny does not mean healthy – and it is not normal not to have a period.’

  • An Apple A Day: A Memoir of Love And Recovery From Anorexia, by Emma Woolf, Summersdale, £9.99
source: dailymail.co.uk