Nothing is more frustrating than when you dedicate yourself to eating healthy, saying ‘no’ to your favorite junk food, and crushing your workouts week after week—only to continue gaining weight despite your efforts. And it’s not as rare as you might think.
That’s because the scale’s reaction to your weight-loss plan is largely determined by the countless chemical messengers, called hormones, that are floating through your bloodstream and body tissue. Together, they decide how fast your metabolism churns, how you build muscle, and where exactly you store those extra calories.
We talked to top weight-loss docs about your all-important hormones, six common problems that could be causing your mysterious weight-gain, and, most importantly, how to get your scale moving in the right direction.
1. Hypothyroidism
About five in every 100 people—most of whom are women—have an underactive thyroid, otherwise known as hypothyroidism, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Hypothyroidism occurs when the thyroid gland, a small, butterfly-shaped gland in your neck, doesn’t produce enough hormones, explains endocrinologist Kent Holtorf, M.D., medical director of the Holtorf Medical Group and a founder and director of the non-profit National Academy of Hypothyroidism. Since your thyroid hormones (called T3 and T4) affect the way your body uses energy, low levels mean that all of your body’s functions (including your metabolism) slow down big time, he says.
How to tackle it: If you suspect your thyroid might be out of whack—symptoms include fatigue, increased sensitivity to cold, constipation, dry skin, weakness, thinning hair, and of course, weight gain—ask your doctor for a referral to an endocrinologist who can perform comprehensive and thorough thyroid testing, Holtorf recommends. Traditionally, physicians have diagnosed (or ruled out) hypothyroidism based only on the amount of thyroid-stimulating hormone (TSH) that your brain’s pituitary gland produces.
However, just because your pituitary gland tells your thyroid gland to get busy, it doesn’t mean that your thyroid gland is actually coming through and producing the thyroid hormones you need, he says. That’s where other testing—for those T3 and T4 thyroid hormones themselves—comes in. Treatment typically involves taking a synthetic thyroid hormone, typically with the name levothyroxine, which gets hormone levels back on track to alleviate symptoms.
Related: Could You Have A Thyroid Issue?
2. Medications
No medication comes without potential side effects and, unfortunately, for a lot of meds, those side effects include weight gain. “I have a lot of patients who gain weight due to the medications they take,” explains says board-certified family and bariatric physician Spencer Nadolsky, D.O., a diplomate of the American Board of Obesity Medicine. The most common culprits include medications for diabetes, blood pressure, and mental health conditions, as well as birth control. Corticosteroids, hormones often included in allergy meds, can also contribute to weight gain, he says.
How to tackle it: Read your meds’ full list of side effects and talk to your doctor about any meds that are linked with weight gain. “There may be other options for you that are weight-neutral or can possibly even contribute to weight loss,” Nadolsky says. If your doctor doesn’t advise switching meds, he or she may have some advice on how to minimize the side effects.
3. Perimenopause and Menopause
As if PMS wasn’t bad enough, fluctuations in estrogen and progesterone that occur during both perimenopause and menopause can lower women’s metabolisms and increase the risk of fat storage. Unfortunately, most of this weight gain occurs around the abdomen, according to research from Monash University in Australia.
Related: The Truth About Belly Fat
How to tackle It: “We cannot stop ‘the change,’ but there are some things we can do to naturally mediate the side effects,” Nadolsky says. For instance, 2017 research published in Menopause found that by participating in a 20-week exercise program, post-menopausal women significantly reduced their weight while simultaneously improving menopausal symptoms like hot flashes and mood disturbances. Talk to your doc about these and other lifestyle changes that might reduce your waistline before opting for hormone replacement therapy.
4. Low Testosterone
“This is one of those chicken-or-egg issues,” Nadolsky says. “A lot of patients gain weight as they age, which then lowers their testosterone levels, which then can further deteriorate their body composition.” That’s largely because fat tissue contains an enzyme, called aromatase, which converts androgens (like testosterone, which promotes muscle-building and fights fat) into estrogens. So, as men’s waistlines increase, their levels of testosterone lower. In fact, research published in Clinical Endocrinology suggests that weight gain (among other variables), not just aging itself, may cause many men’s testosterone levels to decline as they get older.
How to tackle it: While getting to the gym to combat low T can be tough (low energy levels are another common side effect), building muscle can go a long way toward reducing fat levels and their effects on testosterone. In one landmark Harvard School of Public Health study of 10,500 men, those who performed strength-training workouts for just 20 minutes a day gained significantly less belly fat over a period of 12 years compared to those who performed the same amount of daily cardio. (Prior research has also shown that strength training triggers the body’s release of testosterone.) Thank you, muscle power!
5. Poor Sleep
Affecting men and women alike—and in a big way—sucky sleep not only makes you less likely to work out and more likely to binge on junk food, it changes the way your body metabolizes and stores calories, according to Nadolsky. Here’s a compelling example: In one University of Chicago study, when dieters slept for 8.5 hours per night, half of the weight they lost came from fat. When they switched to sleeping only 5.5 hours per night, their rate of fat loss dropped by 55 percent—even though they were following the exact same diet. Holtorf notes that getting less-than-optimal shut-eye results in increased levels of stress hormones including cortisol, which can increase the tendency to store calories as abdominal fat.
How to tackle it: Get more sleep—whether on your own by setting a bedtime and upping your sleep hygiene (turn off those gadgets!), or with the help of a sleep medicine physician. If you’re clocking lots of time between the sheets but still feel groggy during the day, you may want to speak to your doc about sleep disorders. Obstructive sleep apnea, for example, occurs in up to 20 percent of adults, according to the National Sleep Foundation, and is strongly associated with weight gain. “If you wake up un-refreshed, snore, or gasp during the night, definitely talk to your doctor about the possibility sleep apnea,” Holtorf says.
6. Polycystic Ovary Syndrome
Affecting one in 10 American women, PCOS is a common hormonal condition that’s associated with small cysts forming inside the ovaries. While its exact causes are not yet clear—its effects are. “PCOS is essentially insulin resistance that affects the ovaries,” says Holtrof, noting that it’s intricately linked with weight gain and problems losing weight. After all, in insulin resistance, levels of the hormone insulin (produced by the pancreas in response to carb intake) get excessively high. As a result, the body ups its production of male sex hormones, called androgens, which can lead to weight gain in women—typically around the middle.
How to tackle it: Apart from weight gain, symptoms of PCOS include irregular menstrual cycles, excess facial and body hair, acne, thinning hair, patches of darkened skin, and skin tags. If you observe these symptoms, talk to your gynecologist, Nadolsky says. Hormonal contraceptives are commonly used to regulate hormone levels in women with PCOS and can help ease symptoms, including weight gain, in women with the disorder. Your doc may also recommend a medication like metformin, to address the insulin resistance.