I spent a year dieting but failed to shift my stubborn lower belly fat… before learning it was actually the warning sign of this hidden hormone disorder. Why experts say you should NEVER dismiss hard-to-shift weight

Having been slender without much effort for much of her life, Mila Habsy was surprised when her trousers began to feel tighter each morning.

The social media manager from Manchester, then 19, had just come off the birth control pill, which she had been taking since she was 16, in the hope of giving her body ‘a bit of a break’.

But within weeks of stopping she began to feel bloated and uncomfortable.

‘Nothing else in my life had changed, so I was confused by what was going on,’ says Mila. ‘I was at a loss for what to do.’

She began exercising endlessly – running miles each evening – as well as dieting. She cut out breakfast and ate small, tightly portioned meals for lunch and dinner. But nothing could get rid of the stubborn fat gradually accumulating around her tummy, hips and thighs. In less than a year, Mila had put on just over three stone – a marked shift from her previously slim frame.

‘I felt so confused and very, very insecure,’ says Mila. ‘I had gone from being quite skinny to bloated. I couldn’t fit into my clothes and had a round, puffy moon face. I couldn’t even look in the mirror, I felt so bad about myself. It was awful – and nothing seemed to shift the extra weight.’

Today, Mila, now 23, looks – and feels – like a different woman. Back to her normal weight, she’s full of energy, has an impressively toned tummy and even works part-time as a model.

Her transformation is not due to a strict regime of diet and exercise, nor GLP-1 medications. In fact, Mila estimates she eats more than she did before.

Instead, she was diagnosed with a condition that explained her sudden, stubborn weight gain: polyendocrine metabolic ovarian syndrome, or PMOS.

Formerly known as polycystic ovarian syndrome (PCOS), it is best known for causing cysts to form on the ovaries, missed or irregular periods and difficulty getting pregnant.

But a growing body of research has shown the condition can also affect the body’s metabolic system – disrupting its ability to convert food into energy.

As a result, many sufferers find losing weight very difficult and are more prone to belly fat that just won’t budge, a phenomenon that has been dubbed ‘PMOS belly’ on social media.

But experts say the symptom isn’t inevitable.

‘PMOS affects one in eight women in the UK, yet nearly half of them may show no obvious symptoms,’ says Professor Dipa Kamdar, senior lecturer in pharmacy practice at Kingston University. ‘As we’re increasingly understanding, the condition can affect the body’s fat storage as well as its reproductive system.

‘As a result, many women with PMOS also store more visceral fat – the deeper, more dangerous kind that wraps around internal organs – around their midsection. They might have slim limbs and a normal BMI, but a rounded belly that just won’t go away even with the most extreme dieting. This can be challenging to address, but it’s not impossible.’

Firstly, it’s important to understand what PMOS is.

Formerly thought of as primarily affecting the ovaries, PMOS is now known to affect the whole body – hence the name change –by disrupting hormones, metabolism, mental health and the cardiovascular system.

Women with PMOS have ovaries that overproduce male sex hormones, known as androgens. This imbalance can cause irregular or missed periods, excess hair on the face or chin, acne and difficulty getting pregnant, as well as ovarian cysts.

But higher androgen levels can also affect the body’s metabolic system by increasing inflammation and disrupting how muscles and tissues handle glucose, eventually leading to insulin resistance. As a result, many women with PMOS experience unexpected weight gain or have difficulty losing weight.

‘Because their fat cells respond differently to insulin, women with PMOS don’t burn energy as efficiently as those without the condition,’ says Dr Adam Balen, professor of reproductive medicine and surgery at Leeds Teaching Hospitals NHS Trust. ‘They also often have abnormalities in their gut hormones, causing a lack of healthy gut bacteria.

‘These differences combine to cause a build-up of excess fat.’

Fat tends to gather around the midsection, adds Prof Kamdar, because elevated levels of androgens direct it there.

‘The female hormone oestrogen causes women to usually develop a pear shape, with most fat accumulating around the hips and thighs,’ she says. ‘High levels of androgens, like testosterone, can override this pattern, instead redirecting fat storage to the midsection, which is where men tend to develop it.’

Over time this can become a damaging feedback loop, research shows, in which more insulin leads to more androgens, while more androgens worsen insulin resistance.

And left untreated, visceral fat can raise the risk of several long-term conditions, including heart disease and type 2 diabetes.

The difficulty, says Professor Balen, is that without addressing the root causes of this fat build-up, it can be extremely difficult to get rid of it.

There is no single cure for PMOS belly, says Prof Kamdar, and many of the supplements said to help on social media have no scientific backing. While medications for the condition often focus on specific symptoms rather than a root cause.

‘Women may be put on birth control to help with irregular periods, while a drug called spironolactone can reduce hair growth on the face and body,’ says Prof Kamdar. ‘Metformin, a type 2 diabetes medicine, can also help reduce insulin resistance – which can help with weight gain and infertility. But these drugs can all cause side effects, and while they manage symptoms they are regarded by some as more of a temporary fix.’

Instead, a combination of dietary changes, regular exercise and better sleep habits are the best way to restore hormonal balance and reduce insulin resistance – paving the way for weight loss.

‘There is no such thing as a PMOS diet, but inherently, the Mediterranean diet will be beneficial for PMOS patients, as it is for everyone,’ says Prof Balen. ‘Avoiding processed foods, eating plenty of fruit and vegetables and cooking with anti-inflammatory agents like olive oil will promote a healthy metabolism.’

Eating at regular intervals is also crucial, says Prof Balen.

‘The first thing people need to do is stop snacking between meals. Eating regularly helps to stabilise blood sugar levels, which lowers insulin resistance,’ he adds.

Studies show exercise can also help the muscles absorb glucose more effectively – lowering insulin and reducing testosterone production. ‘I usually recommend women with PMOS do three hours of moderate activity and two hours of vigorous activity every week,’ says Prof Balen. ‘This can be a combination of cardio and weight-bearing exercise, but there is no one thing that is best.’

Finally, any stress on the body can worsen symptoms, says Prof Kamdar. ‘Improving sleep can have a huge impact on PMOS,’ she says. ‘Poor sleep worsens insulin resistance, increases the “hunger hormone” ghrelin and increases oxidative stress, making it harder to reduce fat stores.’

For Mila, it took trial and error to find a routine that worked. Today, she starts her day with breakfast containing 30g of protein and lots of fibre before going for a walk.

‘I try to hit 10,000 steps a day,’ she says. ‘I also do pilates or barre classes, and weight training between four and five times a week.’

She doesn’t drink caffeine on an empty stomach and has swapped dairy milk for almond or coconut milk. As for sweet treats, she sticks to a few squares of dark chocolate when she has a craving.

‘It worked for me,’ she adds. ‘I feel so much brighter and happier now.’

Doncaster-based GP Dr Dean Eggitt says: ‘If you’re experiencing stomach fat that won’t budge, don’t hesitate to bring it up with your doctor. There may be hidden causes that no amount of diet or exercise will solve.’