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weight gain

The conditions that cause unexpected weight gain

When it comes to shedding the pounds, there's no substitute for a good diet and a healthy lifestyle. However, if you feel you are doing all the right things and still failing to lose your excess weight, it may be that you are suffering from an underlying health problem. We look at the conditions that might be causing your excess weight.

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Hypothyroidism - a condition in which the thyroid gland does not produce enough thyroid hormone - can cause the metabolism to slow, making it harder for sufferers to maintain a healthy weight. Other symptoms include fatigue, cold intolerance, constipation and muscle weakness.

If you're concerned, your GP can perform a simple blood test to diagnose the condition, and there are treatments available. However, usually losing excess weight will involve more than just prescribing the right dose of medication to treat the disorder.

"If you do have hypothyroidism, some people do find that when their thyroid is treated, they will lose weight," explains GP Dr Julie Coffey. "However, this only tends to happen when patients have a good diet and lifestyle - you can’t medicate away poor choices."

Sleep problems

If you're carrying a bit of excess weight, the last thing you'd expect to help would be to spend more time resting. However, lack of sleep is an often-overlooked cause of weight gain.

"Sleep problems are probably the most common cause of weight gain, although this is not always recognised," explains Coffey. "Lack of sleep has a direct effect on important hormones - ghrelin and leptin. Ghrelin drives our appetite, and when you're sleep-deprived, levels go up and you end up eating more."

"Leptin is a hormone that makes us feel full when we've eaten; in a sleep-deprived state these levels go down, so not only is your appetite increased, you need more food to feel full," she explains.

"Most adults need 7.5 hours of sleep a night - so, 8 hours in bed with the lights out. Many of us don’t prioritise sleep, but it’s so important for our health."

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Polycystic ovary syndrome

As well as causing fertility problems and excess hair in women, polycystic ovary syndrome (PCOS) may cause sufferers to gain or retain weight. Diagnosis often only occurs when women seek help for fertility problems, and usually involves blood tests to measure hormone levels as well as an ultrasound of the ovaries.

Whilst there is no specific treatment for PCOS, those suffering from the condition can still address their weight issues with diet and exercise.

"With this condition you have to be hot on your lifestyle and diet," explains Coffey. "However, sometimes women don't have weight gain at all, so it's not a foregone conclusion."

Type 2 diabetes

Whilst type 1 diabetes is an autoimmune condition that often causes sufferers to lose weight before diagnosis, type 2 diabetes is often associated with being overweight or obese.

As type 2 diabetes is caused by poor diet and lifestyle, it will not be the cause of patients' initial weight gain. However, once the condition is developed, sufferers can fall into a vicious circle that may lead to additional gain.

"If people get quite severe symptoms they may need to take insulin," explains Coffey. "Unfortunately, insulin can lead to additional weight gain both as it increases your appetite and because patients tend to eat more to keep blood sugar levels stable." Some commonly prescribed tablets for type 2 diabetes, called sulfonylureas, also regularly cause weight gain.

However, whilst this outlook may seem a little bleak, it is possible to put your type 2 diabetes into 'remission' - in other words, to bring your blood glucose back to normal levels, even allowing people to come off blood glucose-lowering medication. While this cannot reverse any damage that has already been done by high glucose levels, it can dramatically reduce the risk of future complications.

"Type 2 diabetes can be put into remission with dietary changes (particularly weight loss), especially if you address it when first diagnosed," explains Coffey. "And even if you do end up on insulin, you can get your medication right down with a change of diet and lifestyle."

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Getting older

As we age, muscle mass tends to reduce, which in turn lowers the metabolism. This is why often people gain weight in mid-life and beyond. However, there are other factors at play, and gaining weight at this stage of life is not inevitable.

“As they get older, people aren't generally as active,” says Coffey. “But it is possible to maintain your muscles and, as a result, improve your metabolism. Middle-age is an invitation to up your game - increase your activity levels, work on maintaining muscle mass, and weight gain needn't become a problem.”


Unfortunately, women at midlife and beyond have another contributing factor to deal with when it comes to menopause.

"Many women put on weight around their middle during menopause," explains Coffey. "Not only are they losing muscle mass because of age, but their oestrogen levels also start to drop during menopause, which creates a tendency to put on weight around the middle. In addition, a lot of women get hot sweats which can disrupt their sleep."

However, whilst it may seem as if women have to swim against the tide in midlife in order to maintain a healthy weight, those who make sensible dietary choices and increase their exercise levels should find that they can avoid midlife weight-gain altogether.

Cushing’s syndrome

Cushing's syndrome is a condition that can cause weight gain. However, the disorder is extremely rare, and the symptoms often quite pronounced.

"Cushing’s syndrome is often caused by a tumour on the adrenal gland," explains Coffey. "This causes sufferers to release cortisol, which is a driver for weight gain."

"However, the weight gain is unusual - often patients get really big around the middle and on the face, but their arms and legs remain quite thin."

"The same sort of weight gain can be caused by taking steroid medication - for example, for severe asthma. If you are worried, talk with your GP about any medications you've been prescribed."

We're all dreaming of the magic solution to counter excess weight. But whilst it's important to eliminate any underlying factors if we are concerned, in the majority of cases improving our intake and upping our activity levels will work wonders on the waistline.

Article history

The information on this page is peer reviewed by qualified clinicians.

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