Eating more slowly could lower the chances you'll still feel hungry after your meal, according to a small new study.
And among people of normal weight, it could also decrease the number of calories consumed, found researchers from Texas Christian University. However, this calorie effect was not seen among overweight and obese people.
"A lack of statistical significance in the overweight and obese group may be partly due to the fact that they consumed less food during both eating conditions compared to the normal-weight subjects," study researcher Meena Shah, Ph.D., a professor in the Department of Kinesiology, said in a statement. "It is possible that the overweight and obese subjects felt more self-conscious, and thus ate less during the study."
The new findings are published in the Journal of the Academy of Nutrition and Dietetics. Seventy people -- 35 normal weight people and 35 overweight or obese people -- participated in the two-day study.
On both days of the study, participants ate lunch in a metabolic kitchen, where their energy speed, eating rate (which is energy intake over the duration of the meal), energy density (which is amount of energy intake for every consumed gram of food or water) and satiety were all measured. For one of the lunches, participants were instructed to eat slowly (by imagining they had all the time in the world to eat, chewing thoroughly, putting utensils down between each bite and taking small bites), while for the other lunch, they were instructed to eat quickly (by imagining they had to finish eating by a certain time, chewing quickly, taking big bites and not putting the utensils down between each bite).
Researchers found that the normal-weight participants consumed 88 fewer calories when they were instructed to eat slowly. Obese and overweight participants also consumed fewer calories -- 55 fewer -- but this was not statistically significant.
Both the normal-weight and obese and overweight participants didn't feel as hungry 60 minutes after eating slowly than they did after eating quickly, and the normal-weight group also reported greater feelings of fullness after eating slowly, compared with after eating quickly.
The two groups also drank more water during the meal when eating slowly than when eating quickly. Researchers noted that this water consumption could have had an impact on calorie consumption, too.
In addition, "the slow eating condition may also have allowed subjects to eat more mindfully and better sense their feelings of hunger suppression and satiety," researchers wrote in the study. "Another mechanism may be that foods that are eaten slowly remain in the oral cavity for a longer period of time and lead to increased orosensory exposure that may be related to lower food intake."
Previously, a 2011 study in the same journal showed an association between eating more quickly and having a higher body mass index. However, this study only found an association, and did not prove that eating faster eating speed causes weight gain (or that having a higher weight causes a person to eat faster).