Obese people feel full sooner than people of normal weight

Obese people take less time to feel full than those of normal weight. Despite this, they consume more calories. A faster speed of eating could play an important role in obesity, according to a study funded by the Swiss National Science Foundation.

The number of people in the world who are obese has doubled since 1980. Attempts to halt the progress of this pandemic are reliant on more accurate knowledge of how obesity occurs. This is what a research group led by Christoph Beglinger at the University Hospital in Basel aimed to find out by comparing feelings of satiation among people of normal weight and those who are obese. In their study (*), the researchers conclude that obese people eat faster. The obese take less time to feel full than people of normal weight, and although they spend less time eating, they consume more calories.

Time to satiation

Christoph Beglinger and his team asked twenty people of normal weight and twenty people who were obese to consume a nutritional drink in the morning, on an empty stomach. The test subjects were allowed to drink as much as they wanted, and as quickly as they wanted. Every three minutes they were required to indicate how full they felt. On average, the obese people reported feeling full after just ten minutes, four minutes earlier than those of normal weight. However, during this ten minute period they consumed on average approximately 85 kcal per minute, compared with around 50 kcal per minute consumed by the test subjects of normal weight. Therefore, despite the shorter period of consumption, obese people consumed around 140 kcal more before they felt full.

Eat slowly

"Eating even just 100 kcal a day more than the recommended amount can cause weight gain," write the researchers in their study. "For this reason, the speed of eating is a potential contributing factor in obesity." Although making changes to people's eating habits is difficult, the new results indicate that treatments focussing on such approaches are correct. "Eating slowly is not only healthy, but it should also help you lose weight," explains Beglinger.