Picture this: you consume a balanced diet rich in fiber, protein, and other essential nutrients. If that’s not enough, you make sure to drink at least 8 glasses of water every day and to engage in at least 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity a week. Yet, you’ve noticed that your loose pants are much tighter than usual and that a few pounds have crept up on the scale. Where on earth has this sudden weight gain come from?

It may come as a surprise, but not all weight gain is linked to a poor diet rich in processed foods or a sedentary lifestyle. Much of the time, the root of sudden and unexplained weight gain can often be something much more serious, such as a medical condition. What’s more, this sudden weight gain may also be accompanied by symptoms such as abdominal pain, bloating, and swelling in the arms, legs, feet or hands.

It’s important to discern the cause of the weight gain, as this will help you and your doctor better determine if it’s a sign of a medical issue. With that said, let’s take a look at the possible reasons as to why you’re packing on the pounds.

11 possible reasons for sudden weight gain

1. You’re battling fluid retention

Fluid retention occurs when the body retains water, causing parts of the body to swell which then translates into weight gain.

Most often, the result of the fluid retention is due to you taking too much salt. As a result, the body retains water weight so that it can better dilute the sodium. You may say that you don’t add salt to your food, but other sources of sodium include salad dressings and sauces, frozen meals, and other processed foods.

Aside from cutting back your intake of the previously mentioned foods, you can also increase your intake of water. 

2. You’re constantly stressed

We live in a fast-paced society so it’s understandable if you find yourself stressed now and then. However, if stress becomes chronic, then you’re highly likely to experience a number of symptoms ranging from migraines, fatigue, and weight gain, as a study published in the journal Cell Metabolism found a strong link between high levels of the stress hormone cortisol and fat mass.

Stress not only elevates the levels of cortisol in the body, but it also increases the levels of the appetite hormone ghrelin and this then leaves you constantly craving carbs. If that’s not enough, it also simultaneously affects the functionality of the hormone leptin, which helps to alert your body when you’re full. This then results in you mindlessly eating, and before you know it, you’ve gained a few pounds.

If you’re looking to manage your levels of stress, you can try adopting stress-relieving practices such as breathing exercises, yoga, listening to music, or even taking some downtime from work.

3. You’re developing insulin resistance

Insulin is responsible for ensuring that the body removes glucose from the bloodstream and stores it in the muscles, liver, and fat. Unfortunately, inflammation and obesity make the body’s cells unable to recognize insulin. This then forces the pancreas to continuously pump out large amounts of insulin, until the cells respond.

High insulin levels then mean that the body remains in storage mode, and this then translates to weight gain. In addition to this, if left unchecked, insulin resistance can lead to pre-diabetes. If left untreated, this may later develop into type II diabetes.

In addition to weight gain, you may be battling insulin resistance if you are also dealing with extreme thirst, hunger, fatigue, and even tingling sensations in your hands or feet. It’s important to consult your doctor. Aside from this, you can also try to get more sleep, stay active, and reduce your intake of refined carbs and added sugars.

4. You’re eating too healthy

Who would have thought that eating a balanced and healthy diet would still put you at risk for weight gain?

According to studies, when one thinks they’re eating something healthy, it then forces the brain to release more ghrelin, which then boosts appetite. Therefore, because you’re eating something healthy, you believe that you can consume an unlimited amount of it. Unfortunately, this is not the case.

Regardless of what you’re eating, it’s important to exercise portion control.

5. Your gut bacteria isn’t happy

Your gut contains a mix of both good and bad bacteria and this delicate balance helps to maintain the health of not just your gut, but the rest of your body, too, including weight gain (1).

An imbalance in your gut bacteria can lead to small intestinal bacterial overgrowth, and this, in addition to weight gain, also triggers bloating abdominal pain and diarrhea. Aside from using antibiotics to address your small intestinal bacterial overgrowth, you can also increase your intake of probiotic-rich foods. These include kefir, tempeh, miso, kimchi, and sauerkraut.

6. You have an under-active thyroid

The thyroid is a gland found in the neck, and it’s responsible for regulating a number of bodily functions. These include metabolism, growth and development and body temperature. According to the American Thyroid Association, 1 in 8 women will develop a thyroid disorder during her lifetime (2).

As it helps to regulate metabolism, an under-active thyroid is likely to be accompanied by weight gain. It may also come with other symptoms that include swelling in the neck, fatigue, thinner, irregular bowel movements, and irregular body temperature. All of these symptoms may point to a thyroid condition that may be hypothyroidism, Graves, or Hashimoto’s disease. Therefore, it’s important to consult your doctor.

7. You’re in perimenopause (or menopause)

Perimenopause refers to the transition period to menopause. It is during this period that the hormone estrogen (which is responsible for regulating menstruation and ovulation) begins to decline. This then leads to, in addition to weight gain around the abdominal area and the hips, irregular periods, hot flashes, mood swings, and changes in your libido.

If you want to address your menopausal weight gain, it’s important to remain active. One should also consume a diet rich in vegetables and whole foods, and to avoid sugar.

8. You may have polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a hormonal condition that affects 1 in 5 women. This occurs when small cysts form within the ovaries. This then disrupts the balance of the hormone estrogen and testosterone. This hormonal imbalance then leads to a number of symptoms that include excess body hair, acne, migraines, irregular periods, and insulin resistance. Insulin resistance then causes weight gain around the abdominal area (which increases the risk for a metabolic disorder).

It’s important to go for a check-up if you begin to experience any of the above symptoms. While there’s no cure for PCOS, the condition is manageable with simple lifestyle changes as well as medication.



9. Your meds are to blame

Medication may come with a lot of side effects, most notably weight gain. The medication either stimulate appetite, slow down metabolism or causes fluid retention.

The most notable types of medication that may cause weight gain include contraceptives, blood pressure medication, steroids as well as anti-depressants. It’s important to not stop taking the medication once you realize that it’s causing your weight gain. Rather consult your doctor and inquire if there are any equally effective alternatives that will not affect your weight.

10. You’re not sleeping enough

Sleep is important for your overall health. Not getting enough will not only increase your risk for depression and heart disease but also for weight gain.

Research published in the American Journal of Clinical Nutrition found a link between getting enough sleep and women consuming less sugar – up to 10 fewer grams – during the day. How come? Maybe because lack of sleep can affect levels of ghrelin and leptin – the two hormones that regulate hunger and appetite.

If you want to ensure a healthy night’s sleep, preferably no less than 7 hours, then try to put away your electronics an hour before bedtime. You can also reduce your intake of caffeine after 3 pm, and you can even create a space within your bedroom that will help guarantee a good night’s rest.

11. You quit smoking

Smoking is toxic and detrimental to once’s health, and finally deciding to quit it can have a number of benefits for your health.

However, the removal of nicotine can lead to sudden and surprising weight gain. This can either be due to the return of your appetite (which nicotine tends to suppress), or the fact that your taste buds have returned and you end up overindulging. Whatever the case, it’s important to watch your intake of foods, once you quit the habit.

Pie Mulumba

Pie Mulumba

Pie Mulumba is a beauty and wellness writer, who has a passion for poetry, natural hair, and skin-care. With a journalism degree from Pearson's Institute of Higher Education, and identifiable by either her large afro or colorful locks, Pie aspires to continuously provide the latest information, be it beauty or wellness, on how one can adopt a healthy lifestyle on a day to day basis.

The content in this editorial is for general information only and is not intended to provide medical or other professional advice. For more information on your medical condition and treatment options, speak to your healthcare professional.