You're eating right and working out, yet your pants keep getting tighter. What's the deal? Could be your thyroid.

A sluggish thyroid -- even one that is just a tad slow -- can cause you to pack on the pounds. Read on to learn who's most at risk . . .

The Thyroid-Weight Connection
As much as 2% of the U.S. population may have an underactive thyroid -- called hypothyroidism. Women over 40 are at highest risk, but anyone can have it. And it matters, because your thyroid -- the tiny gland right below your Adam’s apple (see how it looks) -- produces hormones that control your metabolism. Too-low levels slow down everything, so your body burns fewer calories. (Use the symptom-checker in this article to see if your thyroid could be out of whack.)

Strategies for Getting Slim
If your thyroid tests fine, try these tips for battling the bulge or getting over a weight loss plateau:

• Revisit how many calories you really need. It changes with age and activity level. This tool can clue you in.
• Double-check your idea of a normal portion size. Here are three tips for picking the perfect portion.
• Get the skinny on your favorite foods. Use this tool to see if they're really waist friendly.
• Are you exercising enough? Find out here.