Excellent article by NYT writer Gina Kolata on why studies about exercise and nutrition are often worthless. And those are just the ones done by people who should know better, such as actual physicians or scientists. We don’t have enough electrons here to get into the idiocy of the “studies” by done by people who could not possibly know better…celebrity trainers, celebrity nutritionists, naturopaths, homeopaths, etc.
Just because someone labels something a “study” and manages to get it published doesn’t mean it has value. The process of peer review of the purportedly “scientific” literature is broken. It is swamp of bias, conflicts of interest, and opacity. When you read a press report about a supposedly groundbreaking finding, follow the paper trail and read the actual paper. See whether it was a well controlled study; was the main data collection method recall-based surveys; did the results really fall outside the secular trend you’d expect to see in the general population; who funded it; who makes money from people believing the result and, consequently, buying a service or product. Those crumbs will lead you, more often than not, to the inescapable conclusion that you are being sold a bill of goods.
The result is a large body of studies whose conclusions are not reproducible. “We don’t know how to measure diet or exercise,” said Dr. Barnett Kramer, director of the National Cancer Institute’s division of disease prevention.
The Upshot|We’re So Confused: The Problems With Food and Exercise Studies