Sleepless nights, bad headaches, and exhaustion.. This was Rosemary's life. "I would turn to food -- especially sugar -- to keep me going and get me through the day without falling asleep," she says. "And I gained 100 pounds in five years because of it!" Several doctors told her it was just the process of getting older, but as her symptoms got worse, she knew it had to be something more. After seeing a sleep specialist, Rosemary was diagnosed with a severe form of sleep apnea. She now wears a breathing apparatus to ensure she receives the proper amount of oxygen while she sleeps. As a result of her diagnosis and treatment, Rosemary has lost 30 pounds in six weeks! Amber can relate to Rosemary -- no matter what Amber does, she constantly seems to be packing on the pounds rather than shedding them. "I've always been an active person, I exercise, I try to eat healthy," she says, "but I just can't seem to stop gaining weight." Dr. Manny weighs in on other causes of weight gain that you might not be aware of: **Sleep apnea.** "First off," Dr. Manny explains, "Rosemary's case is actually very common among Americans. Sleep apnea causes you to stop breathing for a few seconds chronically throughout the night. It causes you to lose sleep, wake up with headaches, causes stress and higher blood pressure and having little or no energy even when you wake up. Doctors may not always be able to diagnose this problem, so you would need to visit a sleep center if you think this may be a problem that you have." **Thyroid condition.** "Thyroid is the second thing that can cause weight gain," says Dr. Manny. "The thyroid function begins to decrease as we get older. So when you don't have that energy as you get older, you many want to get tested by your doctor to find out how well your thyroid is functioning." **Birth control pills.** "Certain types of birth control pills can potentially lead to weight gain because the hormones in the pill can slow down your metabolism," Dr. Manny says. **Anti-depressants.** Dr. Manny believes they can also slow down your metabolism overall so your body doesn't have as much of the energy it needs to function at normal levels. "I tell women who are taking anti-depressants to complement their medicine with exercise to help keep them moving and create a balance in the metabolism," advises Dr. Manny. Dr. Manny suggests that there are four additional factors that may contribute to weight gain: • Steroids • Stress • Diet soda • Tumors • Over-exercising "What you really need to do is consult your doctor -- and even get a second opinion -- if you feel something is wrong with you," cautions Dr. Manny. "If you know that you are eating too much or making too many of the wrong food choices, I think nutritional counseling is also a very good idea and very helpful."