Acid reflux is a common disorder that affects more than 7 percent of the American population. The disease generates symptoms such as heartburn, throat inflammation and pain, difficulty swallowing and difficulty breathing. The symptoms of acid reflux have a pronounced recurrent character and they generally persist in time. Symptoms such as heartburn and chest discomfort tend to intensify at night or after meals.

Acid reflux involves regurgitation of the stomach's content inside the upper levels of the esophageal tract. The disorder is usually caused by acquired or genetically inherited physiological dysfunctions such as high pressure inside the abdomen or inappropriate activity of the lower esophageal sphincter (ring-shaped muscular valve that connects the esophagus to the stomach). Although inappropriate diet and unhealthy lifestyle greatly contribute to the occurrence of acid reflux, the disorder generally occurs on the premises of physiological abnormalities.

Obesity is a common risk factor of acid reflux disease. Due to increased abdominal pressure, overweight people are commonly confronted with acid reflux. However, recent studies have revealed the fact that even the slightest gain in weight can facilitate the occurrence of acid reflux. Medical scientists claim that people who experience difficulties in maintaining a constant weight are very likely to suffer from acid reflux.

Until recently, the connection between acid reflux and body weight was vague and in the absence of conclusive evidence, medical scientists could only speculate upon this matter. However, latest studies in the field have confirmed the existent theories regarding the involvement of weight gain in causing acid reflux disease.

In order to reveal clear links between acid reflux and body weight, researchers have calculated the incidence of the disease in women, judging by the BMI (body mass index) of the subjects. More than 10.000 women that participated to the study had to complete a questionnaire which asked if they have been confronted with acid reflux in the past. The women that participated to the study were also asked about the intensity, the frequency and the duration of their symptoms. Around 20 percent of the participants stated that they have suffered from acid reflux in the past. A smaller number of participants were still confronted with the disease at the date of the study. More than 50 percent of the participants claimed to have experienced moderate or intense symptoms of acid reflux disease.

The study revealed very interesting facts, as the incidence and the seriousness of the disease increased gradually according to body weight ratios. The women who had a BMI under 20 were 30 percent less likely to be affected by acid reflux disease than those who had a BMI above 20. Thus, the risk of acid reflux has proved to increase proportionally with BMI. Although medical scientists have disregarded aspects such as the age factor, the study clearly suggests the implication of weight gain in causing acid reflux disease.