Thursday, June 18, 2009

Impaired Feeling of Fullness Might Explain Overeating in Obese Individuals

Scientists may have discovered a physiological link that explains why obese individuals tend to overeat and gain weight as a result.

According to research from the Miriam Hospital, the study, published in Obesity Surgery suggests that some individuals who are continuously exposed to specific foods lose their sensitivity to those foods, and as a result they feel less satisfied when eating them. In order to compensate for the lack of feeling full or satisfied, they eat more.

The researchers in this study compared rates of saliva output in both normal-weight and obese individuals using cotton rolls placed in the mouth while they tasted lemon juice a total of ten times. In obese patients, rates of salivation did not decrease across the trials, compared with normal-weight participants. In other words, in normal-weight individuals, after being exposed to a specific food many times, the food becomes less attractive and feelings of fullness or satisfaction with the food increases, causing salivation to subside. In contrast, in obese patients, it takes longer for them to feel satisfied, they continue to salivate at the same rate, and as a result, they tend to over eat.

According to Dale Bond, PhD, of The Miriam Hospital's Weight Control and Diabetes Research Center focused on habituation, "The failure of [severely obese individuals] to habituate suggests that satiation, or the feeling of fullness while eating, is impaired in this population. This could play a role in the inability of some severely obese individuals to regulate or control the amount of food that they eat during a meal"

The good news is that, more and more, we're learning about the deeper-rooted causes underlying obesity, and that there's more to obesity than just 'eating too much'. Hopefully some day in the near future we'll be able to help individuals suffering from disordered patterns of eating just the same as we treat other diseases and illnesses.