We look at how hypothyroidism may trigger weight gain and discover natural ways to support healthy thyroid function.

Everybody knows nutritious food and regular exercise are key to maintaining a healthy and strong body. But what if your weight has crept up a couple of notches on the bathroom scales, despite a balanced diet and regular workouts?

One reason for unexpected weight gain might be an underactive thyroid. This butterfly-shaped gland, located next to your windpipe, is part of your endocrine system which produces hormones.

The thyroid gland controls metabolism which means it’s in charge of how efficiently you turn food into energy. So, if it’s underactive, you may store calories as fat instead of burning them off.

How common is an underactive thyroid?

About 1.3 million people have an underactive thyroid (hypothyroidism) in the UK.

It’s ten times more common in women and is more likely to occur as you get older. In addition, eight per cent of women (and ten per cent for women over 55 years) have subclinical hypothyroidism, which is a mild version that often goes untreated.

A lack of iodine can also be a factor in an underactive thyroid. Your body needs iodine (from fish, seaweed, and eggs) to make thyroid hormones but deficiency is rare in the UK as there’s usually enough in our diets.

Your general health affects your thyroid hormones

‘Healthy thyroid function is vital for your wellbeing,’ says Dr Ghazala Aziz-Scott, a specialist in integrative women’s health at the Marion Gluck Clinic (mariongluckclinic.com). ‘Your thyroid gland produces hormones to regulate your metabolic rate, as well as impacting heart, muscle, digestion, brain and bone health.

‘It releases hormones thyroxine (T4) and triiodothyronine (T3), which is the more active form. T4 is converted into active T3 in organs like the liver or kidneys, meaning your general health affects how well your thyroid hormones work,’ she says.

The gland can become underactive if it gets inflamed, which prevents it from functioning properly. Infections such as a virus – flu or mumps, for example – can cause thyroid inflammation. As can an autoimmune condition known as Hashimoto’s thyroiditis, which is a common cause of hypothyroidism. It’s where your immune system mistakenly destroys thyroid tissue, so the gland can’t make enough hormone.

‘It’s linked to leaky gut syndrome where food and other particles leak through the intestines, causing an immune reaction. A gluten-free diet can significantly improve Hashimoto’s. Sugar and processed foods also cause inflammation in the body and slow conversion of thyroid hormone into its active form,’ says Dr Aziz-Scott.

Why do thyroid problems cause weight gain?

Symptoms of an underactive thyroid include fatigue, dry skin and hair, sensitivity to cold, brain fog, heavy periods and often weight gain. So, what’s the reason for increased weight?

‘Thyroid hormones regulate how efficiently your body burns food for energy. An underactive thyroid makes less hormone, so your metabolism slows down and calories are stored instead of used, meaning you might pile on the pounds,’ says Dr Aziz-Scott.

You can have a blood test to measure thyroid hormone levels, although T3 active hormone levels are not routinely checked. Instead, thyroid-stimulating hormone (TSH) screening is used by the NHS. Mildly elevated TSH levels are considered sub-clinical so may not initially raise red flags with your GP.

A synthetic thyroid hormone tablet, levothyroxine, is used to treat an underactive thyroid. But you can get bioidentical thyroid hormones and a full testing from specialists.

5 natural ways to support your thyroid

1 Make upgrades to all areas of your life

‘You can lose weight with an underactive thyroid, however, it may take longer as your metabolism is slower. This can be frustrating. Instead, focus on feeling better by boosting overall health, rather than obsessing about weight loss targets,’ says medical herbalist Pamela Spence (pamelaspence.co.uk).

‘Make small positive changes to improve your mood, sleep, food, and energy levels. do a bit extra every day – a gentle exercise routine, earlier bedtime, or new healthy recipes. Keep a note of which changes work for you, so you can track your progress.

‘Your thyroid likes routine and dislikes inconsistency. So, irregular sleep patterns or snacking can disrupt the cortisol cycle or spike blood sugar, and trigger stress hormones. Get into a routine of regular sleep times and regular, healthy meals – and stick to it. Your thyroid will function better and your overall health will improve.’

2 Reduce stress levels

If your thyroid test results are near normal but you still have symptoms, the cause could be long-term stress. Perimenopause is a typical time for first experiencing underactive thyroid symptoms. ‘your stress-regulating adrenal glands are under increased pressure, having to produce oestrogen as the ovaries reduce production and eventually stop. Elevated stress hormones slow thyroid function and can cause weight gain,’ says Pamela, who recommends the following:

  • Supplement with the herb ashwagandha as this supports the adrenal glands. its botanical name Withania somnifera, means sleep-inducing, so take it at night. Try Pukka’s Wholistic Ashwagandha capsules (£16.95 for 30, boots.com).
  • Try liquorice, which slows the breakdown of the stress hormone cortisol, meaning tired adrenals have less work to do. It also contains phytoestrogens to balance fluctuating hormones. It’s best absorbed in tinctures – try Liquorice Tincture (£12.95 for 100 ml, indigo-herbs.co.uk). The soothing effect of both these herbs can be felt within days but taking them for three or more months allows your adrenals to calm down. (Avoid liquorice if you have high blood pressure.)

3 Skip caffeine

‘An underactive thyroid causes fatigue, but drinking caffeine for energy is like poking your adrenals with a knitting needle! Too much adrenaline floods your system, triggering a stress response. replace coffee and black tea with herbal tea,’ says Pamela.

  • Choose chamomile or lemon balm tea to help you calm down.
  • For an energy boost, rosemary is a traditional herb great for improving memory and cognitive function. Add one or two sprigs to a mug of hot water and brew for 10 minutes. let the rosemary water cool and sip throughout the day to stay focused.
  • Chew cardamom pods if your energy is flagging. Or steep them in boiled water to make tea. Crush the green pods to get maximum flavour.

4 Eat foods that nourish your thyroid

‘Increase your intake of nutrients that support thyroid health, including iodine, selenium, tyrosine and zinc,’ says Michelle Sanchez, naturopath, nutritionist and medical herbalist from the college of naturopathic medicine (naturopathy-uk.com).

‘These minerals and amino acid help the body produce the thyroid hormone T4, and also convert it into the active form of T3 so it can be used efficiently.

‘Food sources include Brazil nuts, almonds, beans, lentils, chickpeas, eggs, pumpkin seeds, sesame seeds and seaweed.

‘A nutritional therapist can advise on supplementation dosage after assessing your blood test results.’

5 Improve your gut function

‘Around 100 trillion microbes reside in the gut, comprising hundreds of bacterial species whose main function is to digest food and extract the nutrients from what you eat, help protect the body against pathogens and enable the immune system to work efficiently,’ says Michelle.

‘Avoid foods that damage the gastrointestinal system, including sugar, refined carbohydrates, gluten-containing foods, pasteurised dairy, fried foods and processed foods. Supplement with probiotics, especially the lactobacillus and Bifidobacterium strains of bacteria, as they help to repopulate your gut bacteria and reduce an overactive immune response. eat more fermented foods such as sauerkraut or kimchi as they are rich in beneficial gut bacteria.’

Walk yourself slimmer in two weeks.