Tuesday, March 17, 2009

"watch portion size," or listen to your body?

I read a little study in the Journal of  American Dietetics Association (JADA) recently. It happens often these days that I finish an article and come up with completely different conclusions.

The title was:

The Effect of Portion Size Information on Food Intake

Basically, they studied 33 non-dieting adults. On three different occasions, they were given different “portion” sizes of pasta like ½ or 1  or 1 1/2 portions. They were informed of the portion size.  They were told that they were comparing sauces and to eat to a level of "comfortable satiety" or comfortable fullness.  What the study wanted to test was if portion size information guided folks on how much to eat. In theory, telling someone they were getting one portion meant they would stop after that portion.

However, the information they were given about portion size did NOT influence the amount eaten. Participants ate roughly the same amount whether they were initially given 1/2 a portion or more than a portion. 


On another note, subjects rated their hunger levels before meals and rated how much they liked different sauces. The best predictor of whether they liked the taste? How hungry they were before the meal.  How does this relate to childhood feeding and your picky- eater? Allowing children to develop an appetite by stopping grazing and spacing meals every 2-3 hours or so will help them accept and like foods more. A hungry (but not ravenous) child will be more willing to try a new food than one that has been snacking on Goldfish all day.

Back to portions...

The conclusion was that telling folks what a "portion" size is may not help guide the amount eaten.  And yet, every weight loss advice/book/article mentions "portion control." 

What I liked about this study was not pointed out by the authors. The subjects all seemed to know how much they wanted to eat. They didn't eat more when faced with a larger portion, they ate the same amount, to "comfortable satiety" when instructed. I actually think this is good news. Perhaps we should start out wellness advice with "eat until you are comfortably full." It is your body, not some external set of rules that dictates how much you eat. This is called intuitive eating.

A caveat is that these were non-dieting adults. I wonder what the difference would have been if the subjects had been dieters. Would they have been able to self-regulate? Would the deprivation of dieting and ignoring of internal hunger cues have led them to eat more? Or perhaps dieters would have eaten less, paying attention to the rules of  "portion" size even if they were hungry? (Friends and patients who are chronic dieters tell me this is a pattern of eating they get stuck in. Skip meals, eat small "portions" like a Healthy Choice meal, arrive home from work ravenously hungry and eat large amounts to a point of being uncomfortably full.)

I don't know, but it seems to point out again that one of the mantras of the weight-loss world of "portion" control is probably not the helpful tool we thought it was. 

I'm not saying pile your plate with 3 pounds of pasta, but start with a reasonable amount, and if you're still hungry, have seconds. Eat with intention, with attention, and listen to, or learn to listen to your body again...

1 comment:

  1. This is fascinating and I'm intrigued by your conclusion! Since I've done Weight Watchers a couple of times, I'm also curious if the results would be different for dieters. But I think the idea that we could re-learn how to listen to our bodies is inspiring!