I'd expect multivitamins to have a strong effect on general satiety if that's true. Do they?
As for OPs theory, it's strange to think of such a thing happening during an obesity epidemic, but many people do seem to be lacking basic nutrients in their diet. I'm not sure how much we can trust our own guts when it comes to seeking out nutritious foods; the majority of people go for sugar and fats when they're hungry, instead of the fruits and vegetables that contain the nutrients they're lacking. It seems our stomachs are not looking out for our best interests.
[1] https://hub.jhu.edu/2013/12/17/vitamins-might-be-harmful/
What's the evidence of that?
Note that 'required' likely means "less than the RDA" and that RDAs are often set on the basis of "having less than this much will imminently lead to some sort of dysfunction" as opposed to "the amount that actually makes your body happy".
We know that B12 needs to be supplemented in people who are deficient, and that medicos sometimes give B12 injections.
We know that pregnant women who take folate supplements have babies with fewer neural-tube defects (spina bifid etc).
We know that we need to put some B vitamins back in the flower after it's milled otherwise the psychiatric wards fill up.
We know that people who ingest less than the recommended daily intake of Chromium (less than 50mcg per day) have more blood sugar disregulation[1].
So why not put these things together in one package, where and when it makes sense to do so.
I'll admit that some multivitamins are badly formulated, and I actively discourage people from taking certain forms of nutrients. Eg. why does any manufacturer put iron oxide or magnesium oxide in their supplements? These things are poorly absorbed and have known negative side effects.
(Obviously specific supplementation where required is good and useful. I object only to the "mix it all together" approach as both unproductive and an attempt to treat a problem in the wrong place.)
https://www.consumerlab.com/answers/Which+vitamins+and+miner...
> did you know that caffeine inhibits iron absorption (among others)
Yes, I'm aware of that.
> And if you have one
See your fist point. Caffeine, and other stressors increase demand, either by reducing absorption or increasing elimination. Some people have genetic weaknesses, or lifestyle factors, that cause them to be prone to needing more of certain nutrients.
To be fair, I generally agree with what you're saying. Throwing it all in a big bucket and hoping for the best isn't very good clinical advice.
There are, however, some good nutritional supplements that have synergistic formulations.
Full disclosure: I studied nutrition and have qualifications recognised in Australia.
Right. Our appetite is adapted for pre-industrial times, when craving sweet berries while they are in season would be a good thing. We're not equipped to handle constant availability of sugared and MSG-laden processed foods that are actually designed to defeat natural satiety mechanisms.
I would be cautious of demonizing fats; unprocessed fats haven't been shown to do much harm. In recent years, even Harvard Med School has backed off of low-fat recommendations, instead saying trans-fats ought to be avoided. https://www.hsph.harvard.edu/nutritionsource/what-should-you...
There's one way in which our appetites do point in the right direction: veggies are tastier and more appetizing when paired with butter or sauce, which also make it possible to absorb fat-soluble vitamins from the veggies.
If you don't have calories your hunger wont be satiated because of energy needs.
Vitamins don't absorb as well as nutrients found in foods (they have a low gut surface area and may not contain the easiest molecules for your body/gut to breakdown into nutrients).
In my personal experience a complete protein powder (like PlantFusion products) has a strong effect on general satiety as well as health unlike vitamins.
and you're not likely to get the best version in that multi vitamin.