Are you the type that downs bags of Goldfish while watching your favorite program on Netflix? Are you always the first to finish at the dinner table? As it turns out, eating fast might be causing you to gain weight.
The Studies
One study found that participants ate much less of a meal when eating slowly (579 calories when eating slow versus 645 calories when eating fast). That 66 calorie difference per meal can make a big difference over a week or month! The slow eating group was also drank more water, was more full (despite eating less) and enjoyed the meal more (although that result wasn’t statistically significant). A meta-analysis that analyzed 22 different studies concluded that there was a small to moderate, statistically significant reduction of calorie intake from eating slowly.
Why Does Eating Slowly Work?
There appears to be two main reasons why eating slower will cause you to eat less. First, it take the brain about 20 minutes from the time you start eating to send signals of fullness to the body. So, if you power down your meal in 15 minutes you are likely to eat past the point where you became full. Second, how full you feel depends not only on how much you actually ate, but also on how much you remember eating. One creative study showed participants either a picture of 300 ml of soup or 500 ml of soup. The actual amount of soup ate by each group was manipulated by a pump in the bowl though, so that half of the 300 ml group actually ate 500 ml and half of the 500 ml group actually ate 300 ml. Right after eating, hunger was not surprisingly determined by how much the participants ate. Interestingly though, 2 to 3 hours after the meal, hunger was determined more by how much the participants remembered eating (which picture they saw). This shows that memory has a substantial effect on fullness. So, eating slowly (and paying attention to your meal) should make you feel less full later in the day.
Conclusion
Don’t expect to lose weight by eating your Big Macs slowly. Eating slowly isn’t a cure for a bad diet. It will, however, cause you to eat somewhat less and feel more full. Maybe best of all, you’ll enjoy the meal itself more. So, slow down!
Citations:
Andrade, Ana M., Geoffrey W. Greene, and Kathleen J. Melanson. “Eating slowly led to decreases in energy intake within meals in healthy women.”Journal of the American Dietetic Association 108.7 (2008): 1186-1191.
Robinson, Eric, et al. “A systematic review and meta-analysis examining the effect of eating rate on energy intake and hunger.” The American journal of clinical nutrition (2014): ajcn-081745.
Wansink, Brian, James E. Painter, and Jill North. “Bottomless Bowls: Why Visual Cues of Portion Size May Influence Intake**.” Obesity research 13.1 (2005): 93-100.