Observational nutritional studies: garbage in, garbage out
Observational nutritional studies are inherently unreliable. I think that’s rather obvious.
And most nutritional studies are observational.
So we have this situation:
…[N]utrition research critics, such as John Ioannidis of Stanford University…point out that observational nutrition studies are essentially just surveys: Researchers ask a group of study participants — a cohort — what they eat and how often, then they track the cohort over time to see what, if any, health conditions the study participants develop.
The trouble with the approach is that no one really remembers what they ate. You might remember today’s breakfast in some detail. But, breakfast three days ago, in precise amounts? Even the unadventurous creature of habit would probably get it wrong. That tends to make these surveys inaccurate, especially when researchers try to drill down to specific foods.
Then, that initial inaccuracy is compounded when scientists use those guesses about eating habits to calculate the precise amounts of specific proteins and nutrients that a person consumed. The errors add up, and they can lead to seriously dubious conclusions.
At times researchers try to control for this by asking people to track their eating by writing things down. People still are unreliable about what they eat, and/or what they write down. It’s not just that they lie to researchers, it’s that they delude themselves as well. And it makes sense, because most people don’t want to concentrate on tracking in great detail what they actually eat, minute by minute and day by day, even when asked to do so.
Not only that, but I would guess that being studied can actually change the eating habits of some people, who eat more “good” foods and fewer “bad” ones for the duration of the study.
Lastly, the science is generally correlational, which is a weak way to study something.
That doesn’t mean that every single thing we know about food and health is wrong. It just means to take it with a grain of salt.
Now, about salt…
[NOTE: More details of the nature and scope of the problem can be found here.]
No surprise there. At times, I will track my eating in order to cut down. Even though it’s just for me, I find it tempting not to record accurately!
I tend to eat less because I measure my food when I’m tracking. So 1 serving measured is often different from what I consider to be one serving. It adds up!
So much junk science… And we keep paying for it.
Observational science says, I’m one of the healthiest almost 50 year old men I see out there. I’ve lost 20 pounds last year and am a healthy weight of 155 lbs at 5’9″ after removing almost all added sugar, reducing as much simple carbs as possible and eating tons of meat, fruits, vegetables (not Keto).
Short of sequestering people, you can’t do science and nutrition.
Remember the two important questions one needs to ask himself regarding any of these “studies”. Question one: Who wants me to believe this? Question two: Why would he want me to believe this?
I conclude that this “nutritional study” is most likely another bit of junk science that will be used to control my freedom to eat what I want, in the quantity I want, when I want to. And the purveyors of this get the added bonus of feeling virtuous about themselves for saving me from myself.
(Man, I really am a cynic.)
Waidmann
“…The average American eats 3,400 milligrams of sodium per day….”
Really?
I’d like to see a lab scientist eat 10 grams of Sodium.
Maybe with a ten gram chaser of Chlorine.
Either on would kill them of course.
Where’s the part where the astonishingly tight Sodium/chlorine bond is ripped apart in the digestive process?
Is that caused by the Hydrogen/Oxygen rift after drinking water?
I remember when salt, sugar and fat were going to kill us all. We were doomed unless we became vegetarians or something similar.
I am currently reading Nina Teicholz’s “The Big Fat Surprise.” She reviews the studies which underlie the USDA’s food pyramid and its advice to avoid saturated fat in the diet. Study after study has the kinds of problems referred to in this post. When we all started eating vegetable oils and avoiding meat and dairy, we followed advice for which the scientific basis was weak, at the very best. Researchers knew what result they wanted, and confirmation bias led them to see their hypothesis supported when it really wasn’t.
About 20 years ago a good childhood friend of mine died of a heart attack, he was a neurosurgeon in his late 50’s and in decent shape. A mutual friend of ours was another doc, a radiologist who worked with my friend and I asked him what the heck happened. The friend told genetics, my friend’s mom and dad had both died too early, in their 60’s from heart complications and that is a problem.
Radiologist Doc went on to tell me he had a great uncle who lived in Oklahoma who was around 110 years old and his uncle had been approached by several health supplement companies to use and endorse their goods. The uncles response to them was no thank you, he ate lots of bacon and eggs, had smoked most of his life and still drank whiskey and had enough money to support his life style. He also came from a family of folks who lived many years so I can buy the fact that DNA probably accounts for most of our health outcome if we live somewhat moderate lives with food and drink.
OldTexan, I think genetics and luck are definitely at work. My paternal grandfather smoked Camels without filters for something like seventy years, and died at 93 (but not of cancer). We wonder how long he might have lived had he not smoked, but the longest-living of his sons, all non-smokers, died at about the same age.
It’s a basic truth of the human condition. Everybody lies.
–Dr. House
huxley:
Even that’s a lie 🙂 .
I always tell my wife that we are not going to get out of this alive.
And don’t forget this cartoon:
https://morningglory2.wordpress.com/2007/01/17/the-golden-years/
neo: House certainly lied!
(That’s another show I loved for six seasons but the writers kept upping the stakes and horror, so I stopped watching.)
As flies to wanton boys, are we to DNA.
It kills us for its sport.
–Shakespeare (with a minor modification)
Everybody lies. Technically, only if they are intentional in their dissembling.
Something like an FDA drug study is probably one of the best or most thorough approaches. At least I hope it is. But I was very surprised to see that those tests routinely detect and factor out something like a 20% placebo effect. Sometimes I have tried to explain this “problem” to people who are experimenting with their diet or over-the-counter drug therapies, a few respond as though I’d called them mentally defective.
Another thing I hadn’t heard of until recently is the “nocebo” effect. These are people who convinced that something they are taking or eating is causing them great harm, even when medical tests prove the opposite.
____
I like some salt and I’m slightly hypertensive, so I use LoSalt. 50% NaCl and 50% KCl. It tastes OK, though a little less strong in flavor.
I’ve also noticed that recently, on occasion, using sea salt on food tastes incredibly good. It’s been decades since the first time I tried sea salt, so I don’t know if I’ve changed or the sea salt changed, but I don’t ever remember it being that good. Or am I imagining it?
That doesn’t mean that every single thing we know about food and health is wrong. It just means to take it with a grain of salt.
I would argue that almost everything we are told about diet is wrong.
When nutritionists not trying to push some diet or fight some supposed evil are asked what we should eat they generally say the same thing — food. Not too much, and include vegetables.
I remember the evil egg. Some things are not forgivable.
“Nutritional” studies, along with sociological and “climate” studies, are among the primary examples of the Decline Effect in modern science.
https://en.wikipedia.org/wiki/Decline_effect
Their occurrence is a direct result of shoddy experiment construction.
Everyone should remember — especially in these days of “Climate Change” — that the Gold Standard of Science is not “Peer Review”, but multiple independent replications of a Double-Blind Experiment.
You damned sure are not likely to get that from “observational studies”.
As to nutrition, I love the term “empty calories”.
You know how you get empty calories? Drink water. Every calorie in it is an “empty” calorie.
Salty snacks and candy don’t have “empty” calories. They offer satisfaction and pleasure. The notion that all our food must serve a purpose is the kind that creates relatively boring food like Graham Crackers.
https://en.wikipedia.org/wiki/Graham_cracker
Yes, we have “perverted” them from their original intent via Smores and Moon Pies (and my personal favorite, breakfast “cereal” from crumbled GCs in milk), but the entire idea was to make your food bland as possible, to turn eating to a chore.
No thanks. While you should match your intake to your daily burn, that’s the extent of real matching needed. Everything else is personal preference (and physiology!!), as long as you take a multivitamin.