medical conditions weight gain

4 Medical Conditions That Can Cause Weight Gain

As we always hear about medical conditions caused by the consequences of weight gain, our blog post today will have a look at four medical conditions that may, on the other hand, cause weight gain!

We’ll discuss:

  • Hypothyroidism
  • Cushing’s Disease
  • Type 2 diabetes
  • Polycystic Ovary Syndrome (PCOS)


Firstly, hypothyroidism may be one of the medical conditions that can cause weight gain.

medical conditions weight gain

The thyroid’s primary function is to regulate metabolism, which is the process by which the body converts food into usable energy so it can move.

The thyroid gland secretes the hormones that regulate your metabolism.

These hormones circulate throughout the body, instructing cells on how much energy to expend and regulating body temperature and heart rate.

When this gland functions correctly, it continuously produces hormones to replace the old.

This maintains your metabolism and, as a result, the bodie’s functions keep running smoothly.

Although the amount of thyroid hormones in your bloodstream is controlled by another gland, the pituitary gland is further controlled by your brain’s hypothalamus.

So when there are low thyroid hormones in circulation, the hypothalamus secretes the thyrotropin-releasing hormone, which causes the pituitary gland to secrete thyroid-stimulating hormone.

Still with me? Great!

So what is hypothyroidism?

Well, it’s a disorder in which your thyroid fails to make and secrete enough thyroid hormone into your body.

This causes your metabolism to slow, impacting your whole body.

This isn’t good for your body weight since your metabolism accounts for around 60% of the calories you burn each day, which is three times as much as physical activity on average.

Hypothyroidism is fairly common. For instance, autoimmune thyroid dysfunction (Hashimoto’s disease), which is hereditary, is the main type of adult hypothyroidism where someone’s immune system mistakenly attacks their thyroid gland, has been shown to be between 10-60% in adults. 

And what about the difference between hypothyroidism and hyperthyroidism?

The main distinction is one of quantity.

The thyroid produces very little thyroid hormone in hypothyroidism while it produces very much thyroid hormone in hyperthyroidism, meaning that as the metabolism slows down with hypothyroidism, as we’ve talked about, the metabolism speeds up with hyperthyroidism.

Because of these effects on metabolism from the two conditions, it may be harder to deal with cold in hypothyroidism and heat in hyperthyroidism.

However, as this blog post targets medical issues associated with weight gain, we will only be talking about hypothyroidism today.

Hypothyroidism can be caused by either a primary or secondary cause.

A primary cause, like Hashimoto’s disease which we’ve spoken about, is a disorder that directly affects the thyroid and causes it to produce low amounts of thyroid hormones.

A secondary reason is anything that impedes the pituitary gland, which means it cannot deliver thyroid-stimulating hormone (TSH) to the thyroid to reach the right levels of the thyroid hormones.

You will need to consult your doctor for further information on whether you may have hypothyroidism or not and possible treatment methods available.

Once you have treatment, the weight should lower. However, you will still need to watch your calories and exercise to lose weight.

To read our blog detailing the fundamentals of successful weight loss, please click the link here

Cushing’s Disease

medical conditions weight gain

Cushing’s disease may also be one of the medical conditions that can cause weight gain.

Cortisol is a hormone that is frequently referred to as the “stress hormone.”

During times of stress, the body secretes an increased amount of cortisol, increasing heart rate and blood pressure.

It also aids in the management of blood sugar, salt levels, and breathing, reduces inflammation, and helps convert food into usable energy.

Further, the hormone assists by shutting down functions momentarily that your body does not require during times of heightened stress, such as digestion and reproduction.

The adrenal glands (two glands above the kidneys), the pituitary gland (below the brain), and the hypothalamus regulate cortisol levels (the part of your brain above the pituitary gland).

Cushing’s syndrome, also known as hypercortisolism, is a disease in which your body generates an excessive quantity of this hormone, which is usually caused by a tumour or medicine.

Fortunately, it is relatively rare, affecting about 40-70 persons yearly out of a million people.

Cushing’s syndrome is typically classified into several categories based on whether or not:

  • The pituitary gland secretes an excessive hormone corticotropin (ACTH).
  • A nonpituitary tumor secretes an excessive ACTH.
  • Excess cortisol is produced by the adrenal glands.

Cushing’s syndrome can also arise in patients who take a lot of glucocorticoids for conditions including asthma and rheumatoid arthritis.

Of all its symptoms, rapid weight gain is the most common, normally occurring predominately in the face, abdomen, chest, back of the neck and face rather than the extremities, which can be still thin.

Other symptoms include a round face, poor healing, diabetes, stretch marks, abnormal hair growth, elevated blood pressure, fatigue, dizziness, weakness and poor sex drive.

Cushing’s syndrome, if left untreated, can lead to infections, blood clots, depression, heart attacks, memory issues, difficulty focusing, high blood pressure, high cholesterol, fractured bones, and type 2 diabetes.

Please consult your doctor for more information regarding this disorder.

Type 2 diabetes

medical conditions weight gain

We have all heard of the impact that obesity has on the development of type 2 diabetes.

No wonder, given 9 in 10 people with type 2 diabetes are overweight or obese.

But what about the impact that type 2 diabetes has on weight gain?

Well, type 2 diabetes can indeed be one of the medical conditions which can cause weight gain.  

Glucose, a kind of sugar, is always present in the blood. It’s a type of energy that is obtained mostly from the consumption of carbs and consequently causes blood sugar to rise.

On the other hand, insulin is made in the pancreas and has several bodily roles, with one being to assist in the movement of glucose from the bloodstream into cells to be used as energy.

To achieve this, insulin levels rise with an increase in blood sugar levels, meaning that insulin will rise alongside the glucose following a meal containing carbohydrates.

Now, in type 2 diabetics, this mechanism no longer works properly.

The body becomes resistant to the insulin signal, meaning insulin is no longer efficient at transferring glucose from your bloodstream.

As a result, blood sugar stays high for the majority of the day

In response, the body keeps producing more insulin as it’s unaware that its cells have become resistant to insulin’s signal.

This is a problem because insulin’s function is not just to allow the blood sugar to enter cells to be used as energy and be taken out of the bloodstream as a result.

It also promotes fat accumulation and stops fat from being released from the fat stores to be used as energy.

Therefore, this is how type 2 diabetes contributes to weight gain.

Further, medication to treat type 2 diabetes can contribute to weight gain, too, as a common way to help type 2 diabetes is through delivering insulin via injection or pump. 

In a study by Fonseca et al. (2013) involving 8,929 participants, it was found that insulin therapy caused significant weight gain. 

And what can be done to combat weight gain while improving blood sugar levels? 

Well, one solution may be to undertake a low-carb Mediterranean diet.

It entails frequent consumption of olive oil and plant foods alongside a modest intake of dairy and small proportions of red meat and consists of 20% proteins, 45% fat (high in good fat) and 35% carbohydrates (Elhayany, Lustman, Abel, Attal-Singer & Vinker, 2010; Lăcătușu, Grigorescu, Floria, Onofriescu & Mihai, 2019).

The low-carb Mediterranean diet also emphasises whole carbohydrates rather than refined carbohydrates and free sugars.

The reason why to select this diet for weight loss is that when it was compared with traditional Mediterranean diets, low-carbohydrate diets, low-fat diets and the American Diabetes Association diet, it obtained the most average weight loss after 12 months of 10.1 kg versus 7.4 kg, 5.3 kg, 3.6 kg and 7.7 kg, respectively (Mancini, Filion, Atallah & Eisenberg, 2016). 

Additionally, the reason to select it to help blood sugar levels is that diets with higher-good fat are thought to improve insulin sensitivity (when your cells are responsive to insulin and so allow glucose to enter cells more efficiently [Good]), while diets that emphasise whole carbs over processed carbs have been found to improve HbA1c levels and reduce insulin resistance (when cells stop responding appropriately to insulin and stop enabling glucose to enter your cells as quickly [Bad]) (Elhayany et al., 2010; Janghorbani & Amini, 2011).

Exercise is another option since it helps to increase insulin sensitivity and decrease blood sugar levels (Colberg et al., 2010).

Exercise has the direct advantage of reducing extremely high blood sugar quantities because it causes glucose absorption from the blood into muscles and organs.

In addition, following meals, 70-80% of the glucose in your body is sent to your muscles.

A lack of muscular mass hampers our ability to remove glucose from the blood.

On the other hand, the more muscle we keep as we age, the more insulin receptors we have and the more it helps our glucose levels.

So by undertaking resistance training two or three times a week, we can further help type 2 diabetes.

However, exercise must be carefully planned with sufficient food and insulin to avoid hyperglycemia or hypoglycemia.

So it’s crucial that if you have type 2 diabetes or are at high risk for it, consult your doctor before beginning any exercise program to know how much your blood sugar should be before and after exercise and the most suitable exercise type for your current health status.

Polycystic Ovary Syndrome (PCOS)

Lastly, PCOS can be one of the medical conditions that can cause weight gain.

Polycystic ovarian syndrome (PCOS) is a common condition that causes hormonal disturbances, irregular periods, and/or the formation of tiny cysts on one or both ovaries, affecting 7% of adult females (Ndefo et al., 2013).

PCOS, like type 2 diabetes, can lead to weight gain due to related insulin resistance.

Also, high insulin levels stimulate the synthesis of androgen, the male hormone.

Abnormal hair growth, acne, and weight gain are all signs of high androgen levels.

Because male hormones cause the weight increase, it usually occurs in the belly.

Men tend to carry more weight in this area. As a result, women with this condition typically have an apple shape rather than having a pear form.

This is concerning since abdominal fat (visceral fat) is the most harmful form of fat, linked to an elevated risk of type 2 diabetes and cardiovascular disease.

As a result, the same treatment techniques used to treat type 2 diabetes can also be used to help people with PCOS battle insulin resistance and weight gain.

Further, weight reduction may assist PCOS because a 5% weight loss can improve insulin resistance, hormone levels, menstrual cycles, and quality of life (Rondanelli et al., 2014).


Therefore, conditions such as Hypothyroidism, Cushing’s Disease, Type 2 diabetes and Polycystic Ovary Syndrome (PCOS) may contribute to weight gain. Again, for more information, please contact your doctor!

For help in finding a path to weight loss that also meets your nutritional needs and avoids the dangers of fad diets, contact us here at Plato Weight Management. We are weight-loss experts and can help you reach your ideal body weight in an effective and evidence-based manner.


Elhayany, A., Lustman, A., Abel, R., Attal-Singer, J., & Vinker, S. (2010). A low carbohydrate Mediterranean diet improves cardiovascular risk factors and diabetes control among overweight patients with type 2 diabetes mellitus: a 1-year prospective randomized intervention study. Diabetes, Obesity and Metabolism, 12(3), 204–209.

Fonseca, V., McDuffie, R., Calles, J., Cohen, R. M., Feeney, P., Feinglos, M., Gerstein, H. C., Ismail-Beigi, F., Morgan, T. M., Pop-Busui, R., & Riddle, M. C. (2013). Determinants of Weight Gain in the Action to Control Cardiovascular Risk in Diabetes Trial. Diabetes Care, 36(8), 2162–2168.

Janghorbani, M., & Amini, M. (2011). Normal Fasting Plasma Glucose and Risk of Prediabetes and Type 2 Diabetes: The Isfahan Diabetes Prevention Study. The Review of Diabetic Studies, 8(4), 490–498.

Lăcătușu, C.-M., Grigorescu, E.-D., Floria, M., Onofriescu, A., & Mihai, B.-M. (2019). The Mediterranean Diet: From an Environment-Driven Food Culture to an Emerging Medical Prescription. International Journal of Environmental Research and Public Health, 16(6), 942.

Mancini, J. G., Filion, K. B., Atallah, R., & Eisenberg, M. J. (2016). Systematic Review of the Mediterranean Diet for Long-Term Weight Loss. The American Journal of Medicine, 129(4).

Colberg, S. R., Sigal, R. J., Fernhall, B., Regensteiner, J. G., Blissmer, B. J., Rubin, R. R., Chasan-Taber, L., Albright, A. L., & Braun, B. (2010). Exercise and Type 2 Diabetes: The American College of Sports Medicine and the American Diabetes Association: joint position statement. Diabetes Care, 33(12).

Ndefo, U. A., Eaton, A., & Green, M. R. (2013). Polycystic ovary syndrome: a review of treatment options with a focus on pharmacological approaches. P & T : a peer-reviewed journal for formulary management38(6), 336–355.

Rondanelli, M., Perna, S., Faliva, M., Monteferrario, F., Repaci, E., & Allieri, F. (2014). Focus on metabolic and nutritional correlates of polycystic ovary syndrome and update on nutritional management of these critical phenomena. Archives of Gynecology and Obstetrics, 290(6), 1079–1092.