Weight Gain: Surprising Reasons You're Gaining (cont.)

When you're tired, you also don't handle stress as well, so you may reach for food as a coping mechanism. Further, you may be taking in extra calories from late-night snacking. Some people think eating might help them get back to sleep, but all it really does is add more calories to their daily total.

Symptoms that you may not be getting enough rest include fatigue, low energy levels, nodding off easily, and feeling irritable.

Strive to get eight hours of sleep each night.

"Add about 15 minutes to your bedtime and see how you feel," suggests May. "Continue to experiment with additional 15-minute increments until you find the ... amount of sleep that is right for you."

When you develop good sleeping rituals and get regular exercise, you sleep better, she adds.

2. You May Be Gaining Weight Because of Stress

We live in a society that demands we do more, be more, and achieve more. Stress moves us forward and helps cope with life's demands, but it also affects our mood and emotions.

"Stress response, whether it is 'fight-or-flight,' juggling too many responsibilities, or coping with financial pressures, triggers a biochemical process where our bodies go into survival mode," explains May. "Our bodies store fuel, slow down metabolism, and dump out chemicals [cortisol, leptin, and other hormones] which are more likely to cause ... obesity in the abdominal region."

Many people reach for food to help ease the stress. But, of course, this doesn't work in the long run.

"Food is a temporary fix because it does not deal with the real stressors that must be addressed in order to reduce the trigger for eating and fix the problem," says May.

Susan Bowerman, MS, RD, assistant director of the UCLA Center for Human Nutrition, says stress eaters tend to prefer high-carbohydrate foods because these foods trigger an increase in the brain chemical serotonin, which has a calming effect. "It is almost like self-medicating," she says. "Many people binge on starchy foods to make themselves feel better."

Both May and Bowerman recommend relaxation techniques as well as exercise, which also burns calories and provides other health benefits.

3. You May Be Gaining Weight Because of Medications

Some prescription drugs used to treat depression, mood disorders, seizures, migraines, blood pressure, and diabetes can cause weight gain, from a modest amount to as much as 10 pounds per month. Some steroids, hormone replacement therapy, and even oral contraceptives may also cause gradual weight creep. Your medicine cabinet might be the cause of your weight gain if you've gained 5 or more pounds in a month without a change in your lifestyle.

"Every drug works a little differently to cause weight gain, from increasing appetite, altering the way fat is stored, to how insulin levels change," says May. "And not all drugs have the same side effects on all people."