At a practical level nutrition isn’t generally a problem, but that says more about the human body / food than the lack of scientific knowledge.
There is a long list of things that cannot be synthesized by people and must be consumed. (Elements like Potassium as well as specific nutrients like Vitamin C and Thiamine being well known.) There’s a longer list of things than can be synthesized but should largely be consumed ex:
Linoleic acid (LA), an omega-6 fatty acid, and α-linolenic acid (ALA), an omega-3 fatty acid, are considered essential fatty acids because they cannot be synthesized by humans.
The long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can be synthesized from ALA, but due to low conversion efficiency, it is recommended to consume foods rich in EPA and DHA.
There’s also a lot of basic facts that get complicated when you dig into them. For example calories produced by burning foods isn’t 1:1 with the calories available to people. Cellulose for example burns but is effectively indigestible. One way to investigate this is to have some eat something and then burn their poop, followed by many studies that do so for various reasons.
There’s also a lot of nutrition science that straddles the line with medicine. Thus there exists many specialized diets for various conditions etc.
There is a long list of things that cannot be synthesized by people and must be consumed. (Elements like Potassium as well as specific nutrients like Vitamin C and Thiamine being well known.) There’s a longer list of things than can be synthesized but should largely be consumed ex:
Linoleic acid (LA), an omega-6 fatty acid, and α-linolenic acid (ALA), an omega-3 fatty acid, are considered essential fatty acids because they cannot be synthesized by humans.
The long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can be synthesized from ALA, but due to low conversion efficiency, it is recommended to consume foods rich in EPA and DHA.
There’s also a lot of basic facts that get complicated when you dig into them. For example calories produced by burning foods isn’t 1:1 with the calories available to people. Cellulose for example burns but is effectively indigestible. One way to investigate this is to have some eat something and then burn their poop, followed by many studies that do so for various reasons.
There’s also a lot of nutrition science that straddles the line with medicine. Thus there exists many specialized diets for various conditions etc.