Where does the average person’s (non-expert) “common knowledge” information about fat come from? I put together the four top sources:
1. Family, friends, schoolyard
2. “Health beat” local/national 6/11 o’clock news
3. Ads for weight loss interventions/pills/etc
4. Our personal care physician (PCP)
#1 is merely an amplifier of the information from #2 – #4.
#2 is reporting on press-release-science — marketing. Most of the studies reported on are the worst kind of junk studies, with the more serious, rigorous, less assertion-filled studies (whose authors or authors’ funders didn’t release press statements about) relegated to the media-silent pages of a serious journal.
For a good example of what a junk-science press release looks like, go here.
#3 is marketing, by definition.
#4 is a tricky one. This is the authority we are taught from birth to venerate, to trust, to obey. However, doctors are not currently required to take a nutrition course in order to get their MD. Additionally, most doctors are strapped for time and hence develop blanket-recommendations for people based on the quickest evaluation – what they look like – without considering more deeply what their actual risk factors could be. Additionally, the idea that fat is a disease and fat kills is “common knowledge” in med school, without any deep qualification. The professors who teach it is “common knowledge” could very well be anti-obesity researchers on Big Pharma’s dole, though I wouldn’t make that assumption about every one. Additionally, some PCPs themselves are not ethical, and take money for promoting weight loss drugs to patients.
So we see that med school itself is heavily influenced by the marketing arm of Big Pharma, and that PCPs themselves can be influenced thusly.
When it comes down to it, in conclusion, all the main sources of the average person’s “common knowledge” about fat are heavily influenced, if not completely determined, by aggressive marketing, and not science.