French Scientists Link Higher BMI with Lower IQ

Xemu writes "French scientists have linked obesity to lower IQ reports the Telegraph. In a new five-year study of more than 2,200 adults, people with a low body mass index (BMI) could recall 30% more words in a vocabulary test than those who were obese. The fatter subjects also showed a higher rate of cognitive decline when they were retested five years later. In the United States, 30% of the population is obese according to OECD. That's the highest rate of obesity anywhere. Do these high obesity rates affect the average IQ of the population?" (Of course, this sidesteps discussion of whether IQ tests measure anything significant at all.)

Comments

IQ Tests

[stevemm81]

(Of course, this sidesteps discussion of whether IQ tests measure anything significant at all.)

This wasn't a general purpose IQ test. It was a specific test of people's ability to recall words. They're talking about memory in particular, not some fuzzy idea of general intelligence.

Memory != IQ

[mkiwi]

It is common in society to associate people with good memories as people with high IQ's.

This is simply not true. If you actually take an IQ test, you will see that it does not test your memory as had been done in the study, but rather your cognitive thinking skills. In fact, there are many people who can memorize history or math equations or whatever, but they come up far short when they have to apply the concepts they memorized.

Again, memorization is not critical thinking, and memorization != IQ.

A truly groan-worthy pun...

[InfinityMinusOne]

to someone speaking dutch. (for the non-dutch, 'slim' means smart in dutch)

Re:BMI is a poor way to measure body fat.

[benzapp]

It's Body Mass Index, not Body Fat Index.

All the BMI measures is your risk for a variety of heart related ailments. The theory is that the more massive you are, the harder your heart has to work.

The issue is most people lack the ability, the financial resources, and the discipline to gain an extraordinary amount of muscle mass. So, in the vast majority of cases, the BMI does measure body fat. But, it has nothing to do with the percentage of your body that is fat or how toned you are.

Just thought I would add that to what you are saying.

study doesn't say anything about "obese" people

[chartreuse0]

I went back and read the actual paper upon which this article is based, and the summary given on Slashdot is rather inaccurate. This article does not claim to compare "normal" weights to "obese" weights. Rather, it purports to show a trend primarily within the normal range of BMI.

In particular, they broke up BMI's into five groups: (1) 15-21.5, (2) 21.5-23.4, (3) 23.4-25.2, (4) 25.2-27.7, and (5) 27.7-45, where BMI's up to 25 are considered normal, up to 30 are considered overweight, and over 30 are considered obese. Even within the final group, not all the participants are obese.

It begs the question of why they didn't compare "normal" weight IQ's to "obese" weight IQ's, as this would be a big story and a more impressive research finding! It's likely that either they didn't have enough obese participants to satisfy statistical significance (so most of group (5) is actually individuals with BMI's of 27.7 to 30), or they didn't find that obese people had lower IQ's. When the BMI groups that they break up their data into as strange as this, and not at all the groups that are normally used in research papers, it begs the question of what kind of data massaging they had to do to find their conclusions. Did they try 100 different breakdowns of BMI groupings until they found one that (barely) satisfied statistical significance?

I remain skeptical as to the conclusions of this paper.