If you read or watch the news, by now you’ve probably seen headlines like this today:
Don’t Skip the Spaghetti! New Study Says Pasta Not Fattening
Eating Pasta Does Not Cause Obesity, Italian Study Finds
Enjoy That Pasta Salad: Noodles Linked to Lower BMI
Pasta Doesn’t Make You Gain Weight, Says Best Study Ever
Any time you see bold proclamations like these from news sources, be wary.
Be very wary.
Why, you ask? The headlines reference a study, so the information within those articles is probably trustworthy, right?
Well…it’s far more complicated than that.
To demonstrate, take a look at some excerpts from the articles listed above:
Carb lovers, rejoice! Now there’s evidence that you can have your rigatoni and eat it too—without an ounce of worry about weight gain. (source)
See the problem with that quote?
How about this one?
There’s good news for Pope Francis — and for the rest of us! Last year, the pontiff was told to trim his waistline and resist temptation when it comes to pasta. But a new study suggests that there’s no need for anyone to skip the spaghetti. (source)
Those are some BOLD statements…and – to make matters worse – they are based on a seriously flawed study.
Most journalists do NOT know how to interpret scientific studies. This leads to misinterpretations of the findings, which in turn leads to a flurry of articles with misleading titles and flawed information…which in turn leads to people following bad advice.
And, some writers get a bit too excited over what they perceive as good news (or, news that will get a lot of attention).
The “Pasta study”, officially titled Association of pasta consumption with body mass index and waist-to-hip ratio: results from Moli-sani and INHES studies, was published in the journal Nutrition and Diabetes on July 4, 2016. For this study, researchers initially enrolled over 23,000 people, but after eliminating many for various reasons, a total of 14,402 subjects were included in the final analysis.
Let’s examine some points from the study and identify the problems with each.
This study aimed at evaluating the association of pasta intake with body mass index (BMI) and waist-to-hip ratio.
Problem: BMI is NOT a good measure of health. A massive study, conducted by UCLA and published in the International Journal of Obesity earlier this year, found that using BMI to gauge health incorrectly labels an estimated 74,936,678 adults in the US as cardiometabolically unhealthy or cardiometabolically healthy. Of that number, 54 million Americans have been classified as “unhealthy,” even though they are not.
Among other findings from the BMI study:
- More than 30 percent of those with BMIs in the “normal” range — about 20.7 million people — are actually unhealthy based on their other health data.
- More than 2 million people who are considered “very obese” by virtue of having a BMI of 35 or higher are actually healthy. That’s about 15 percent of Americans who are classified as very obese.
And, there’s an additional twist: Another study – also conducted earlier this year – found that a low BMI and high body fat percentage are independently associated with increased mortality in both men and women. Having a lower BMI isn’t necessarily a good thing! So, using BMI as a health measure for this study was not an optimal choice.
The European Prospective Investigation into Cancer and Nutrition (EPIC)-food frequency questionnaire and one 24-hour dietary recall were used for dietary assessment.
For this study, questionnaires, mailed guidance notes for participants to help them estimate portion sizes, and telephone interviews were used to track food intake and physical activity.
Participants were instructed to write down what they ate and drank, and how much they exercised. They reported that data to researchers via telephone 24 hours later.
Problem: Self-reported data has long been KNOWN to be seriously flawed and thus unreliable for use in studies. In a paper published in the International Journal of Obesity last year, researchers wrote of self-reported diet and exercise data, “[The data] are so poor as measures of actual [energy intake] and [physical activity energy expenditure] that they no longer have a justifiable place in scientific research.”
This problem was hinted at in one article about the pasta study:
Lastly, due to incorrect data provided by some participants, especially women, when either describing their body type or recalling their meals, the researchers at first linked pasta with obesity during a “crude analysis.” When they corrected for underreporting, eating pasta was found not to contribute to obesity.
The paper also says that body weight and height were self-reported, and that information was used to calculate BMI. As the publication notes, “Self-reported BMI data tend to over- or under-estimate in proportion to measured BMI.” Researchers categorized participants as either “physically active” or “inactive” based on self-reported information.
Problem: People also over and under-estimate their weight, height, and activity level. By a LOT. Studies have shown this OVER and OVER. It is a KNOWN issue. The researchers acknowledged that people tend to over or under-estimate BMI data, but think that people are going to report their weight and height accurately? That doesn’t make any sense!
Pasta as the traditional component of Mediterranean diet (MeD) was studied for its association with obesity indexes.
BIG problem: What IS a “traditional Mediterranean diet”?
This study focused on people who live in Italy, but that country isn’t the only one that follows a “Mediterranean diet.” The researchers never defined what they meant by MeD.
Defining the MeD IS problematic, because it varies by region: there are many different “Mediterranean diets” among different countries and populations of the Mediterranean basin. This is due to ethnical, cultural, economical, and religious diversity.
People who live in Mediterranean countries tend to eat more saturated fat. In Northern Italy, lard and butter are commonly used in cooking, and olive oil is reserved for dressing salads and cooked vegetables. In both North Africa and the Middle East, sheep’s tail fat and rendered butter are traditional staple fats.
In fact, the mythos of the Mediterranean diet might be based on some flawed science too, as Nina Teicholz, author of the fascinating and well-researched book The Big Fat Surprise, explained in an interview with Dr. Frank Lipman:
The Mediterranean Diet originated from a survey of the eating habits of long-living Cretan peasants in the 1950s, who seemed to eat very little meat or dairy. However, they were surveyed shortly after WWII, when their economy was in ruins. Also, their diet was sampled during Lent, when animal foods were severely restricted. The data was therefore not any good and never grew any better. In fact, the reason that the Mediterranean Diet became celebrated and famous is that researchers fell in love with the sun-kissed, enchanting Mediterranean—and most of their studies and travel were funded by the olive-oil industry. It’s amazing how researchers, including some of the most respected people in the field today, thrived on the Mediterranean Diet conference junket. The actual science is far from impressive: it can only show that this diet is superior to the failed, low-fat diet (and what diet isn’t?). Tested against a higher fat diet, the Mediterranean regime looks far less impressive for weight loss or heart disease. Also, no one’s ever been able to pinpoint any special, disease-fighting powers of olive oil—which turns out not to be an ancient foodstuff after all but a relatively recent introduction to the Mediterranean diet.
In the actual published study, under “conflicts of interest,” the researchers said
The authors declare no conflict of interest.
Problem: The study was partially funded by Barilla…which happens to be a company that makes pasta, a fact that is casually mentioned in a vague blurb in the press release that was posted (in Italian) on the website Neuromed.it:
The study was partially supported by Barilla Spa through the MISE (Italian Ministry of Economic Development) Within the frame of the ATHENA program MI01_00093 – New Technologies for Made in Italy (PII OF MI 6/3/2008) and Epicomed Research Srl
Just because a study is funded by an industry or company that stands to benefit from results in their favor doesn’t mean the research itself is flawed, but…take a look at this, from the published paper’s Results (emphasis mine):
Both in women and men, the obese population was older and at lower socioeconomic status, had higher waist and hip circumferences and waist-to-hip ratio, and consumed more pasta (grams per day) than normal or overweight participants.
Dr. Andreas Eenfeldt, a Swedish doctor who runs the website DietDoctor.com, tied these two points together perfectly:
Can pasta make you slimmer? Probably not, but after a whole lot of statistical magic from a new study (partially funded by a pasta company), the answer becomes yes.
Lots of media outlets happily publish this Barilla-funded click-bait, apparently without actually looking at the numbers in the study.
Just one tiny problem. The study data showed the opposite. Obese people – both men and women – ate more pasta! Thin people ate less pasta.
So how come the conclusion of the study and the media headlines say the exact opposite? Well the researchers made some “adjustments” to the data.The researchers basically assumed that the participants must be lying and changed black into white using their statistical tools. And thus, even though obese people ate more pasta in the study, the bizarre conclusion became that pasta protects from obesity.
And then we have this…
According to The Washington Post:
The study recommended deriving 10 percent of your daily calories from pasta.
Problem: 10% of WHAT daily calorie allotment? How many people actually know how many calories they need (or actually consume) on a daily basis? Let’s make some basic calculations here. If the average person is “supposed to” (per arbitrary, general “guidelines”) consume 1,500 to 2,000 calories per day, then according to this study, 150 to 200 calories of that “should” come from pasta? Why? What benefit does that offer? No reason for that recommendation is given (but one might suspect it serves to benefit companies that sell pasta).
The Post went on to say:
This doesn’t justify every pasta decision, of course. Olive Garden’s fettuccine Alfredo dish, which totals 1,480 calories and provides nearly three times your daily need for saturated fat, is a no-no.
Problem: Three times whose daily need for saturated fat? Again, arbitrary numbers based on…nothing. And – the saturated fat is likely far less of a concern than the refined carbs in the pasta! The truth is, we NEED fat in our diets, dietary cholesterol has not been proven to cause heart disease, and sugar and refined carbohydrate “foods” (including pasta) are quite damaging to health.
If something seems too good to be true, it probably is. Nutrition studies are, by nature, hard to conduct and are often flawed. View sensational headlines that make bold proclamations with a skeptical eye. Seek out various sources of information. Wait for more information before making big decisions about your health.