Monday, July 11, 2016

Hyped Up Headlines: Eat Pasta! Lose Weight!

Here's what one of many headlines read last week: "Pasta Helps You Lose Weight, Study Reveals". I really want to love this headline. I really want to believe this headline. But this, and many, many other news outlets got this study so, so wrong. In full disclosure, I love pasta. I eat pasta - several times a week. I have an Italian-American mother and between her and my grandparents, we got fed a lot of pasta growing up. My grandfather used to say "A day without spaghetti is like a day without sunshine". 

But, as much as I want to, I can't love these headlines, because they have totally mangled the results of this study. The study is a "cross-sectional observational study". It used two different sets of data. In one study, researchers used a method called a "24-Hour Recall" to gather information about how people ate. This method sounds just like what it is: "What did you eat yesterday". So the researchers basically looked at how much pasta the study participants ate on one day and then looked at their body mass index (a measure of weight for height). Studies that asked people what they ate are prone to bad information because most of us aren't very good at remembering what and how much we ate. And one day of what you ate? Well, you can see how flawed that data is. 

And then we have the observational nature of the study. These types of studies are very limited in what they tell us. These studies cannot, I repeat CANNOT, show cause and effect. All they show is correlations or associations. Even if this data had been better, it still could not have shown that eating pasta caused lower body weights. Eating pasta could just be an innocent bystander and it was really something else that the pasta-eaters were doing that made their body weights lower. 

So, here's my take on pasta. If you eat too much pasta, it could pack on some pounds. If you eat pasta within the number of calories you need, you probably won't gain weight. Maybe there is something about pasta that helps keep weight lower. But this study does not tell us that. 

And yes, that is Audrey Hepburn eating pasta. 

Beth Kitchin, PhD, RDN
Assistant Professor, Nutrition Sciences
University of Alabama at Birmingham 

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