Weight gain shockers slideshow: Surprising reasons you're gaining weight

Why are you gaining weight?

If you start taking in more calories than usual or cut back on exercise, you wouldn’t be surprised if the numbers on the scales crept higher. But what if you're doing everything the same as you always do and your weight still goes up? It's time to delve a little deeper into what might else be going on.

Lack of sleep

There are two issues at work with sleep and weight gain. The first is intuitive: If you're up late, the odds are greater that you'll eat some late night snacks that will increase your calorie intake. The other reason involves what's going on biochemically when you're sleep deprived. Hormones that affect appetite take over, making you hungrier the next morning. These hormones also make you feel less full after eating.

Stress

When life's demands get too intense, our bodies go into survival mode: Cortisol, the 'stress hormone,' is secreted, which causes an increase in appetite. We may also reach for high-calorie comfort foods in times of stress. This combination is a perfect breeding ground for weight gain.

Antidepressants

An unfortunate side effect from some antidepressants is putting on weight, which may occur in up to 25% of people taking them long-term. Talk to your GP about changing to another drug if you think your antidepressant is causing weight gain. But remember that some people experience weight gain after beginning drug treatment simply because they're feeling better, which leads to improved appetite.

Corticosteroids

Anti-inflammatory steroid medications are notorious for causing weight gain. Fluid retention and increased appetite are the main reasons. Although weight gain is common, the severity of this side effect depends on the strength of the dose and length of time taking the drug. Some people may also see a redistribution of fat while taking the drug -- to places like the face, back of the neck or the abdomen. If you have any concerns about the side effects of a medication, talk to your GP.

Other drugs that may cause weight gain

Several other prescription drugs have been associated with weight gain. The list includes antipsychotic drugs (used to treat mood disorders like schizophrenia and bipolar disorders), as well as medicines to treat migraines, seizures, high blood pressure and diabetes. You and your GP should be able to find a medication that treats your symptoms without disrupting side effects.

'The Pill' does not typically cause weight gain

Contrary to popular belief, combination contraceptive pills (oestrogen and progestin) do not usually cause weight gain. In fact, some women on the pill lose weight, primarily from nausea. If you're still concerned about possible weight gain, talk to your GP.

Hypothyroidism

If your thyroid (the butterfly-shaped gland in the front of your neck) is not making enough thyroid hormone, you're probably feeling tired, weak, cold and gaining weight. Without enough thyroid hormone, the metabolism slows, making weight gain more likely. Even a thyroid functioning at the lower end of the normal range might cause weight gain. Treating hypothyroidism with medication may reverse some of the weight gain. If you have any concerns, please talk to your GP.

Menopause

Don't blame the menopause and the loss of oestrogen for your midlife weight gain. These all may occur around the same time, during your 40s or 50s, but changing hormone levels probably aren't the cause. Ageing slows the metabolism, so you burn fewer calories, and any changes in lifestyle (e.g. exercising less) play a role. But where you gain weight may be related to menopause, with fat accumulating around your waist, not around your hips and thighs.

Cushing's syndrome

Weight gain is a common symptom of Cushing syndrome, a condition in which you are exposed to too much of the hormone cortisol, which in turn causes the weight gain and other abnormalities. Cushing's syndrome can occur if you take a corticosteroid for a condition such as asthma, arthritis or lupus. It can also occur when your adrenal glands produce too much of the hormone. The weight gain may be most prominent around the face, neck, upper back or waist.

Polycystic ovarian syndrome (PCOS)

PCOS is a common hormonal problem in women of childbearing age. Most women with PCOS grow many small cysts on their ovaries. The condition leads to hormone imbalances that affect a woman's menstrual cycle – and can lead to excess body hair growth and acne. Women with this condition are resistant to insulin, which may cause weight gain. The weight tends to gravitate to the abdomen, putting women at greater risk of heart disease.

Stopping smoking

On average, people who stop smoking gain about two to four and a half kilos (four to 10 pounds). Why? First, nicotine curbs your appetite so that once you stop you may feel increased hunger pangs, which leads to overeating. Nicotine also increases your metabolism, but many people don't decrease their calorie intake to compensate for the slowdown after they quit smoking. Lastly, nicotine is notorious for dulling the taste buds, so you may find food tastes better once you kick the habit, which can lead to overindulgence.

Rule 1: If you do gain weight …

Don't stop taking any medication without first consulting your GP. Recognise the importance of the drug you're taking. It may be critical to your health.

Rule 2: If you do gain weight …

Don't compare yourself with other people taking the same drug. Not all people have the same side effects on the same medication. Even if one drug caused someone else to lose weight, the same might not be true for you. Talk to your GP if you have any concerns.

Rule 3: If you do gain weight …

Don't panic if the weight gain is just from water retention, which is not permanent weight or fat. Once you've finished taking the drug or the medical condition is under control, the puffiness from fluid retention may subside. Stick to a lower salt diet in the meantime.

Rule 4: If you do gain weight …

Ask your GP about alternative drugs you can take. In most cases, your doctor can put you on another medication that may not have the same side effects.

Rule 5: If you do gain weight …

Find out if the weight gain is from a decrease in metabolism - from either a medical condition or medication. And if so, take the time to start metabolism-raising activities. Get moving!

More reading on weight gain

• Smoking cessation and weight loss
• Am I overweight or obese?
• How to take control of stress
• Getting a good night's sleep
• Types of depression
• Home remedies for depression
• What is polycystic ovarian syndrome?