Eat Slower, Eat Less
If you eat more slowly, chances are you will eat less and weigh less, according to two studies published in the "Journal of the American Dietetic Association." The first examined the relationship between self-reported speed of eating and BMI among 1,601 randomly selected middle-aged women from New Zealand. The women filled out surveys that included questions on weight and demographic information in addition to a question about their speed of eating. The women were asked to indicate their usual rate of eating: very slow, relatively slow, medium, relatively fast, or very fast. After controlling for factors such as smoking and menopausal status, the researchers found that each category increase in the speed of eating was associated with 2.8% increase in BMI. This is the equivalent of a 0.72 unit increase in BMI or a 1.95 kg (4.29 pound) increase in weight for a woman with a BMI of 28.8 (the average BMI in this study). Weight loss of the magnitude has been linked to lower risk of developing diabetes and cardiovascular disease. One main limitation of this study was the reliance on self-reported weight and eating speed. The second study provided more objective information on the effects of eating speed on calorie intake. In this small study, researchers looked at the impact of wearing a bite counter on calorie intake among 30 university students. The students wore the bite counter on their wrists during three meals: one in which they did not get feedback about bite rate, one were they could view feedback on their bite rate on a computer screen as they ate, and a third meal when they were given a target rate of reducing their bite speed by 50% (slow bite-rate condition) and got feedback on how well they were doing. Overall, compared to when they got feedback, the students ate 70 fewer calories during the slow bite-rate condition. The effects of eating more slowly varied by baseline calorie intake. People who ate more than 400 calories at the first meal benefited most from decreasing their bite rate. They ate 142 fewer calories during the feedback meal and 164 fewer calories during the slow bite-rate condition than they did at the first meal. Please note the limitations of these studies. The first relied on self-reported information, which is liable to bias, while the second was a small, short-term study. More research is needed to assess the impact of bite speed on calorie intake and BMI.
1231-35 (Aug. 2011).