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Why You're Gaining Belly Weight and Cannot Lose it 

If your clothes are fitting too tight and you're experiencing unexplained weight gain, here's seven reasons that could explain why. 
FACT CHECKED BY Emilia Paluszek

If you've noticed unexplained weight gain, but your eating habits and physical activity level hasn't changed, there could be an underlying medical reason for putting on extra pounds. There's several conditions that can cause sudden weight gain and getting to the bottom of it is vital for your overall health. "While there is no specific definition for what is considered rapid weight gain, it shouldn't be ignored, according to Sharon Orrange, MD, an internal medicine physician at Keck Medicine of USC and clinical associate professor of medicine at the Keck School of Medicine of USC. "Either the patient considers it noticeable enough to come in for a visit, or their body mass index measured during our visit has jumped from the normal weight to overweight category, or from the overweight to obese category," she explains. "Both deserve a discussion and intervention." Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.




Thomas Gut, D.O. Associate Chair of Medicine at Staten Island University Hospital tells us, "Medical conditions like slow thyroid can make you  gain weight. Certain hormonal disorders can result in reduction of basal metabolism which can contribute to increases in weight over time."

Keck Medicine of USC states, "If you can't otherwise account for your weight gain, your doctor may want to test you for certain endocrine disorders. The endocrine system, which includes adrenal glands, thyroid and ovaries, helps regulate hormones that control several functions in the body. "These are rarely an explanation for weight gain but worth a look," Orrange says. "Irregular periods, acne and weight gain in women may indicate polycystic ovary syndrome, and fatigue may suggest an underactive thyroid (hypothyroidism)."


Prescription Medications

Female doctor talking while explaining medical treatment to patient through a video call with laptop in the consultation.

According to Dr. Gut, "Some medications for diabetes, depression or even seizure disorders can result in unintended weight gain via many different mechanisms. It's often possible for your doctor to switch you to a different medication without the weight gain effect."



Thoughtful girl sitting on sill embracing knees looking at window, sad depressed teenager spending time alone at home, young upset pensive woman feeling lonely or frustrated thinking about problems

Keck Medicine of USC says, "Depression is also associated with changes in appetite and weight gain. In addition, "people with seasonal affective disorder, or SAD, may also gain weight," Orrange explains, "but treating SAD may help them avoid it."


Quitting Smoking

no smoking sign

The Mayo Clinic states, "Quitting smoking is often associated with weight gain. And for some, it can lead to enough weight gain to qualify as obesity. Often, this happens as people use food to cope with smoking withdrawal. In the long run, however, quitting smoking is still a greater benefit to your health than continuing to smoke. Your doctor can help you prevent weight gain after quitting smoking."



man stressed on couch

The Mayo Clinic explains, "Many external factors that affect mood and well-being may contribute to obesity. People often seek more high-calorie food when experiencing stressful situations."


Not Getting 7-9 Hours of Quality Sleep Every Night

woman sleeping at night with eye mask

According to the Mayo Clinic, "Not getting enough sleep or getting too much sleep can cause changes in hormones that increase appetite. You may also crave foods high in calories and carbohydrates, which can contribute to weight gain."


Slow Metabolism

unhappy woman sits on couch, hand on forehead

The North American Menopause Society states, "Many women gain weight during the menopause transition. This weight gain is sometimes blamed on menopause or on treatment for conditions related to menopause, including hormone therapy.  However, there is no scientific evidence that menopause or hormone therapy is responsible for midlife weight gain.

Age and lifestyle are the main culprits. Aging and lifestyle seem to be the primary culprits behind weight gain in women around the time of menopause. Aging is associated with slowing of the metabolism. Lean body mass decreases with age while body fat accumulates throughout adulthood. The bottom line: you have to "run to stay in place."

Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more about Heather
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