Millions of Americans complain of bloating. About 1 in 10 Americans regularly complain of bloating, sometimes so severe they can't button their jeans.

Bloating is caused by excess air trapped in the intestinal tract.

Gas-producing foods are often the culprit. A study published in Critical Reviews in Food Science and Nutrition confirmed that they can cause gastrointestinal problems, but experts agree that everyday habits you may never have considered may be a big cause.

Below are six habits that, according to dailyburn.com, make you bloated:

1. Chewing gum. When you chew gum, you also swallow some air which expands your intestines. In addition, the sugar alcohols in gum can also cause gas.

2. Eating too fast. When you eat too quickly, you inhale excess air. Taking time to chew food thoroughly helps break it down for digestion.

3. Using a straw. Drinking through a straw also adds air to your digestive system.
"Every time you sip through a straw, air comes up before the liquid," Bonnie Taub-Dix, author of Read It Before You Eat It, tells dailyburn.com.

4. Snoring. If you feel bloated in the morning, you were likely snoring or sleeping with your mouth open, says David T. Rubin, M.D. of The University of Chicago Medicine.

Rubin says that most people who have sleep apnea complain of morning bloating.

5. Eating fiber. Adding too much fiber to your diet at once can also cause excess bloating. Also, check the ingredients of packaged foods for inulin, a form of fiber that's hard on the stomach.

6. Being stressed. In addition to the havoc caused by hormones influenced by stress, it can also cause you to eat too quickly, take in excess air when anxious, and postpone bathroom breaks. Try relaxation therapy.