I have been collecting a long list of incorrect scientific (or pseudo-scientific) claims. I’m going to publish some of them here. Maybe this will become a regular feature.
For most of human history “old age” meant anyone over 30.
That is true for the last 10,000 years but during the Upper Paleolithic, say 30,000 ago, it was not true. There were actually quite a few people who lived to be older than 30. Although horticulture and then agriculture allowed human populations to increase, it also resulted in modern humans becoming shorter and having shorter lifespans. In all likelihood the dietary changes made possible by growing things had those effects.
All people need to do to lose weight is eat less.
Again, that’s a half-truth. The sad fact is that two different people can eat effectively the same quantities and types of foods and effectively get the same amount of exercise but one will gain weight while the other will lose weight. Some people are naturally thin while others are naturally fat. It’s hard to figure out why.
I refer to (calories consumed) – (number of calories expended through exercise) = weight loss/gain as the “simple thermodynamic theory of diet”. It is false. There are more variables including body mass, muscle mass, heredity, gut biome, etc. There also seems to be something to the “set point theory”, the notion that human bodies can more easily maintain some weights than others.
That doesn’t excuse people from overeating. It may well be much harder for some people to maintain a healthy weight than others. Life is not fair.
I’m accepting nominations for other false scientific (or pseudo-scientific) claims. To be accepted nominations must be falsifiable. It’s not enough for them to be theoretically wrong or that you disagree with them.
“I refer to (calories consumed) – (number of calories expended through exercise) = weight loss/gain as the “simple thermodynamic theory of dietâ€. It is false.”
And its called that in the literature and, yes, its false. (The first time I heard you talking about this I was skeptical, but took it upon myself to investigate.) It turns out that the evidence is quite robust, and pretty well understood. (Although it continues to be fought by a hidebound medical profession still tied to the thermodynamic/low fat high carb/frequent eating model.) Hormonal interactions – basic human physiology – explain almost all of it. There are various medical commentators, and underlying studies published in the NEJM, available if you do cursory searches.
Fundamentally, metabolic rate will go down with plain caloric restriction, especially with frequent calorie ingestion. Failure to lower insulin, and related hormonal reactions are the cause.
If insulin is driven down norepinephrine and growth hormone sympathetic reactions will keep metabolic rate up.
Dave Schuler: Some people are naturally thin while others are naturally fat. It’s hard to figure out why.
Periodic famine will result in the evolution of some people being obese during times of plenty.
Life expectancy always means “at birth,†unless otherwise specified. Throughout all of human history (300,000 years), the highest death rates occurred among children. If you could reach age five, you likely would live to 70. But half of all children died before five. In the Roman era, one’s “floruit†was in the 40’s.
The other important cause of death among the hunter-gatherers and neolithic farmers was murder. A substantial fraction of young men were murdered. When the Celts took over southern Britain, they killed 90% of the male neolithic farmer men.
A complexity in weight loss I didn’t mention is that there’s more than one metabolic pathway. Some bodies use one; others another. Some change based on conditions. That may be hereditary; it may be epigenetic; it may be influenced by the gut biome.
“A complexity in weight loss I didn’t mention is that there’s more than one metabolic pathway.”
I’m not sure exactly what you mean by that. Glycogen levels stored in the liver are rather quickly depleted. Fundamantally, all of us will switch to triglyceride (stored fat) fuel sources when glycogen is depleted, or or newly eaten food is unavailable. Its how man, since neanderthal man, compensated for the episodic availability of killed or gathered food. We alternatively either burned or stored fat. And insulin is the hormone that acts as the switch.
I can’t speak to the gut, but I rarely see it cited. It seems like the glycogen/triglyceride pathways dominate.
Like to nominate:
Compound interest on savings will benefit you financially.
How popular must the belief be? Most of what you describe is stuff that has never really been supported by an science but are beliefs held by a minority or even in some cases a majority of the population based upon their cultural beliefs or pseudo-science. We had a lot of stuff like blacks cant play quarterback or a woman couldn’t be a CEO. The latter makes it hard to met the falsifiable criteria.
Take the vaccines causing autism claim. Every good study done, and some are incredibly large and well done, shows this is not true. We know that the guy who started the claim lied. We know that the lie attracted a lot of grifters who made a lot of money off the claim. We know there is no physiological or pharmacological basis for the claim. But for followers of pseudo science they think they have falsified the claim that vaccines do not cause autism but pointing at kids who get diagnosed with autism around the same time they got vaccinated.
We no longer have, across the broad culture, accepted standards for scientific reasoning and/or statistical interpretation. Everyone is an expert. You can always find someone with claimed expertise to support whatever you want to believe. Look at your weight loss claim. The science, the real science, supports your claim but while i am too lazy to go looking for it would bet that there is no shortage of experts who claim you are wrong and have “evidence” to support their claims.
Steve
Steve
What inspired me to write about each of those was running across each of them twice in alleged science journals this week.
I enjoy all of your learned thoughts but must disagree. I guarantee that anyone who does not eat will lose weight and in fact will be quite skinny upon dying of starvation.
Perhaps I should have been more precise. “Lose weight while preserving health” would be more accurate. The key point is that those espousing the simple thermodynamic model are treating obesity solely as a moral failing. At the very least that’s an exaggeration.
I wonder if the logical outcome of the simple thermodynamic model is what’s referred to as “yo-yo dieting” which is probably worse for you than remaining overweight.