In the context of the article, I'm pretty sure this relates to nutritional value for ducks, not humans. Birds and people can eat a lot of the same food but our metabolisms are optimized very differently. I read one article that compared raising horses on a diet of corn to raising children on a diet of chocolate. After all, horses' metabolisms are optimized for extracting nutrition from grass. I would imagine ducks are on the opposite end of the spectrum.
Sure, I don't dispute the health risks of excessive starch and sugar consumption for either ducks, horses or children, but the nutritional value of starch and sugar is very real indeed. Animal cells rely on glucose as their primary source of energy, you can't get more real than that.
I get what they intend to say, but when they use categorical language like that at least one word has to yield its actual meaning, whether it's 'nutrition', 'real' or 'value'. It's a bit like the Clintonian interpretation of 'is'.
You're making an assumption that because glucose is part of the process, it is essential to ingest it through sucrose, fructose, starches, etc. For humans at least, this isn't really the case as it's possible for the body to produce glucose from fat and protein when no polysaccharides are being ingested, and function normally and indefinitely doing so. Without water, vitamins, sodium, iron, etc., the body will experience problems it cannot compensate for.
Starch(in general) is considered a nutrient, but not because it can be used to produce glucose.
>You're making an assumption that because glucose is part of the process, it is essential to ingest it through sucrose, fructose, starches, etc.
No, that's not what I'm assuming or implying.
I'm saying because starch is a highly efficient source of glucose, it has nutritional value.
Nobody who are saying citrus fruits have nutritional value because they are high in vitamin C are implying it's essential to ingest vitamin C through citrus fruits. You can't blame a lemon for not being the exclusive source of vitamin C, neither can you blame white bread for not being the only way to increase your blood sugar.
>Starch(in general) is considered a nutrient, but not because it can be used to produce glucose.
What else is it good for but to be converted into glucose?
> you could easily survive on chocolate alone for years
Seems like quite an extreme claim. I'm not disagreeing, I simply don't know, but is this surviving with no ill effects (rickets for example) or surviving in the sense of just being alive?
I suspect it would be "just being alive" because I imagine eating chocolate alone would come with a whole host of other problems over a long period of time (including scurvy). I'm not sure vitamin D deficiency would be an issue if you were stranded on an island with limited shelter.
However, there is something to be said for chocolate's nutritional value in special circumstances. Most modern military rations include chocolate or chocolate-flavored items in some form as a significant part of their caloric value (predominantly fats and carbohydrates, even for the flavored items, as your OP mentioned). Aside from its propensity to melt, its size and weight make it somewhat convenient to carry on patrol and for lightweight rations, calorie-dense items are important.
I'm sure there's probably some literature on its use in rations that may be a good starting point, but as far as I remember from watching far too much Steve1989 on YT [1], most of the historic survival rations--think plane crashes--tended to rely on candy, malted milk tablets, or compressed oatmeal/cornflake bars rather than chocolate.
I've linked his channel below because I think you might find it fascinating.
It's more about having enough fiber, chewing and overall time spent eating (which is good both for their intestinal tract and their wellbeing) than about extracting nutrition from grass.
