Recently an article was published looking at the caloric intake of children at various ages and the relationship of this intake to their weight. The article was published in the respected journal Pediatrics and picked up across cyberspace in various medical information processing and reporting sites. What was not picked up were the little words: “not statistically significant.”
Deeply held beliefs, paradigms, and explanations of the world that make intuitive sense whether or not they represent reality, probably hold the advancement of science back more than any other thing. It’s easy to look back at the religious persecution of Galileo and marvel at the ignorance that punished a man for busting the prevailing paradigm of his day, it is much more difficult to face our own preconceived notions and understand how they can be as powerful as any prejudice from the sixteenth century. Researchers are human too, and as prone to preconceived notions as the rest of us. Only rigorous scientific training stands between them and ignoring data when it conflicts with their preconceived notions – or at least that’s the concept. In practice, data is faithfully reported but less rigorously interpreted, leaving the reader of scientific articles often with the wrong idea.
So, overweight girls over the age of nine and boys over the age of twelve actually turn out to eat fewer calories than their thinner contemporaries. This finding was statistically significant. But overweight kids younger than this ate more than their thinner contemporaries. This finding apparently did not reach statistical significance and yet it is the finding receiving the most press and driving recommendations and speculation. How can this be?
Given the data, one would think it wise to challenge the prevailing notion that fat people necessarily eat more than thin people. But no. The non-significance of the findings gets glossed over during the interpretation as well as in re-reporting. And this, my friends, is not harmless. Suddenly people are worried that their very young children might be eating too much.
I worry that parents, in an attempt to avoid a condition (obesity) that their own child might not even be prone to genetically or environmentally, may begin to practice calorie restriction at home. And calorie restriction is far from harmless. First, it hyper-focuses the brain on eating. Hunger does that. Second, it encourages—nay, mandates– food hoarding and secret eating, in extreme cases bingeing. Third, caloric restriction nearly always involves fat restriction, which reduces satiety (and worsens one and two above). But—far worse— caloric restriction can impact growth, especially brain growth.
So let’s be careful, be very careful: it is more important to have a brain which is fully developed and able to function at its genetic top speed intellectually than it is to be a certain body size. Besides, I hope it is clear to everyone that we understand obesity and overweight so poorly that conflicting articles appear nearly every week with findings that challenge the paradigm of “calories in and calories out determining weight.” Some of these articles are interesting, some are poorly done, some are incomplete….. suffice it to say, the picture is very cloudy. And until it is clear, I suggest we are cautious before we calorie restrict children or burn anyone at the stake for heresy. Today’s heresy may be tomorrow’s science.