Does Eating too Quickly Contribute to Obesity?

Posted By elissa on May 16, 2008 | 2 comments

When I was a kid, my best friend and I would often stop at a local fast food restaurant called the Red Barn, for a burger, soda and fries.  She’d be finished with her entire meal before I’d eaten even half of my burger…one time, she nearly made me choke from laughing, as she went through an elaborate pantomime of me, eating sooo slooowly.  I tried to eat faster at times, but it was hopeless – I just couldn’t seem to manage it. 

When we were teens, she and I were about the same size: a Junior Size 5.  When she got married in her late 20’s, I was still wearing a 5/6…while her wedding dress was a Size 9.  The last time we talked, she lamented that she’d “never see 180 lbs. again.” 

I’m still pretty much the same size I was in high school…and still a slow poke at the table.

Interestingly enough, my husband is also a fast eater: in the past, he’d be finishing seconds before I was even close to being done with my first (and usually only) serving.  And not unlike my friend, he was skinny as a young guy, but steadily gained weight with the years.

Coincidence?  I don’t think so.  And there are a couple of Japanese studies that agree with my observations: there’s a relationship between eating rate and weight…and overweight.

The first study looked at 1,695 18 year old female college students.  After collecting the (self-reported) data on weight, height and eating behavior, the authors performed a statistical analysis on the data.  They discovered that mean BMI was higher by 2.2 kg/m², 1.5 kg/m², 1.0 kg/m² and 0.5 kg/m² for the “very fast,” “relatively fast,” “medium” and “relatively slow” groups, respectively, relative to the “very slow” group.  The second study looked at an even larger number of men and women (4,742) between the ages of 35 – 69.   The researchers not only looked at their current BMIs in relation to eating rates, but also their (self reported) BMIs at age 20.  They found correlations between eating rate and current BMI AND the change in BMI from age 20 to the present.

What is there about eating quickly that leads to greater weight gain?  Fast eaters apparently consume more calories…the authors of the second study also noted a correlation between eating rate and caloric intake.  So one possible mechanism is that fast eaters are “ahead” of the signals the stomach sends to the brain to indicate fullness.  The researchers also proposed a second mechanism, based on a different study that demonstrated rapid eaters have reduced insulin sensitivity.

In my experience, another factor may be in play: the actual foods being eaten.  Simply put, some foods are a lot easier to eat quickly than others.  It’s a snap, for example, to scarf down a bowl of pasta or a soft, freshly baked Cinnabon.  It’s a lot tougher to inhale an apple or a plate of broccoli – that stuff takes a while to chew through, and has fewer calories in the bargain.  Needless to state, that’s precisely how we “tricked” my husband into eating more slowly, as he embarked on the battle of the bulge.  Rather than force him to eat more slowly, we simply added a large pile of crisp-tender vegetables to each meal.  Seconds weren’t forbidden, but the veggies had to be eaten first.  Needless to state, he could put away a serving of – say – lasagna in 2 minutes, but it took a lot longer to chew through the green stuff.  Thus – by the time he was finished, and had also downed a large glass of water – he had zero appetite for seconds.

Today he’s 210 lbs.  It’s been slow going at times, but the scale (and calipers) have been on a steady, downwards trajectory for five years now.

The moral of the story?  It’s not just about what – and how much – you eat…it’s also about how fast you eat it.  If you’re trying to drop some weight, it will pay off to slow things down.