You’re eating healthy and exercising regularly. You don’t even look at desserts. So why aren’t those extra pounds melting off? Turns out, there are reasons (many not even related to food at all) why your best attempts to fight fat could be failing.

Here are factors that could be sabotaging your weight loss goal and what you can do about them.

Stuck in the middle

Hitting your forties? Pushing 50? We hate to tell you this, but so-called middle-age spread isn’t a myth. That’s because mid-life is associated with a slowed down metabolism. So even if you’ve always been slim and you keep eating the same number of calories and exercising as much as always, you may still pack on extra weight.

Several studies have shown that women gain an average of 12 to 15 pounds during the years around menopause. However men don’t escape the tendency to add pounds with age, either. In fact, there’s about a five percent decrease in metabolic rate for both sexes per decade and, according to Laurey Simkin-Silverman, Ph.D., assistant professor of epidemiology at the University of Pittsburgh, most adults tend to gain an average of a pound a year at mid-life.

Thankfully, there are ways to avoid expanding waistlines and "love handles" as you age:

• Rev up your metabolism by increasing exercise. Pamela Peek, MD, author of Fight Fat After Forty, advises adding weight training to your workout because increased muscle tissue burns more calories than fat tissue.
• Stick to a plan of increased physical activity and a low-fat, reduced-calorie diet. University of Pittsburgh researchers found that doing those two things prevent weight gain in menopausal women and helps with weight loss, too.
• Practice yoga. A study by Fred Hutchinson Cancer Research Center scientist Dr. Alan Kristal and colleagues concluded middle-age people who practiced yoga gain less weight over a ten-year period than those who did not, independent of other physical activity.

Weight gain from your medicine cabinet

Many prescription medications and even some over-the-counter drugs increase weight by slowing the body’s metabolism, stimulating appetite, or causing fluid retention. For example, several medications prescribed to control seizures are notorious for causing rapid weight gain and even the pain reliever ibuprofen can cause the scales to edge upwards in some people.

Of course, no one should stop or change a prescribed medication without first talking to your doctor. However if you have noticed unexplained weight gain after taking a drug, do discuss it with your health care professional. Sometimes simply a dosage adjustment or changing to a different drug can solve the weighty problem of med-caused extra pounds.

Older antidepressants including tricylics (Elavil and Tofranil) and MAO inhibitors (drugs like Parnate and Nardil) have long been associated with substantial weight gain.When the newer SSRIs (selective serotonin reuptake inhibitors) like Prozac, Lexapro, Paxil, and Zoloft were developed, they didn’t seem to cause this problem. However, as more and more people have taken SSRIs over time, statistics now show that about 25 percent of people who take these antidepressants for six months or more do experience some weight gain.

If you’ve experienced extra pounds on an SSRI, trying a different antidepressant under your doctor’s direction may help. For example, Effexor and Serzone generally do not cause weight gain, and Wellbutrin can cause weight loss in some people.

There’s one medication that you can no longer blame on causing extra pounds – birth control pills. It turns out blaming extra weight on the pill is more myth than medical fact. New research conducted by scientists at Oregon Health and Science University and recently published in the journal Human Reproduction concludes the commonly held belief the pill leads to weight gain is false.

The low thyroid connection

Gaining weight and you can’t figure out why? If you have some other problems like fatigue, feeling cold a lot, body aches, dry skin, and constipation it’s a good idea to see if you have hypothyroidism. About five percent of the U.S. population has the condition, according to the National Institutes of Health (NIH).

People over fifty and women are at highest risk but low thyroid can affect men and young people, too. The American Thyroid Association recommends that all adults be screened for thyroid problems every five years, starting at age 35, with a blood test that measures the amount of thyroid stimulating hormone (TSH). TSH is produced by the pituitary gland and tells the thyroid gland to make and release the hormones thyroxine (T4) and triiodothyronine (T3).

If your TSH is low, medication can help alleviate symptoms, including weight gain. Medication can also help protect from more serious problems associated with long term hypothyroidism in later years, such as an increased risk of heart disease.

New research from Newcastle University in the United Kingdom shows marginal, or subclinical, hypothyroidism affects up to 16 percent of women and 6 percent of men and often precedes full-blown low thyroid disease. In the recent study, patients undergoing 12 weeks of treatment with the thyroid medication thyroxine saw a marked improvement in cholesterol levels and a reversal of weight gain.

Other unexpected weight loss pitfalls:

• Obstructive sleep apnea (a decrease or cessation in breathing while you sleep) is a diet danger. Not only does it raise the risk for hypertension and cardiovascular disease, now researchers at the University of Arizona College of Medicine have found a link between sleep apnea and weight gain. Seek medical help for apnea symptoms, including snoring and non-restful sleep.
• Burning yourself out on the job can add pounds. A large population study carried out by the University of Helsinki found that work-associated fatigue and too much overtime are associated with weight gain, possibly because workaholics tend to eat-on-the-go and lack enough healthy physical activity.
• What you don’t know about sweeteners can make you fat. A Princeton University research team has demonstrated that high-fructose corn syrup causes more weight gain, especially in the abdomen, than table sugar even when their overall calories are the same.
• Don’t be fooled by "diet" foods that are loaded with calories. A nice salad for lunch sounds like a safe bet for sensible eating, but do some detective work before you indulge. A typical restaurant’s extra large Caesar salad with chicken, tossed with salad dressing, has a whopping 1,100 calories and almost 100 grams of fat.

Sherry Baker is a writer from Atlanta, Georgia. She last wrote the article Computer Vision Syndrome for Synergy. Sherry can be reached at featuredstories@adamcorp.com