I used to think this too, but read in a bunch of places that corn is a pretty nutritious food. So it tastes good and it’s good for you. I also usually just take half an ear, but not always … I add a little bolus - maybe an extra unit. I think it’s a pretty high glycemic index, as it seems to move through my blood glucose pretty quick.
Corn is great when cycling - when I did Ragbrai I had one or two ears every day. No worries.
I think people think this because they pass the indigestible hulls thinking that the whole thing passed through. If corn had zero nutritional value there would be no need to bolus for it.
Yep, guilty as charged! I heard (but didn’t research myself which isn’t usual for me) that it’s got very little nutritional value “which is why it passes through the digestive tract and comes out the other side not really broken down.” But as you say, really only the hull is what passes through. All the stuff inside each hull is actually quite high in nutrition! Now that I actually researched it, I learned something new (thanks to you guys for pointing me to do my due diligence!).
Looks like it actually provides fiber which aids in digestion (insoluble fiber, which makes it a low glycemix value food and slow to digest), plus folate, thiamin, phosphorus, as well as many B vitamins and essential minerals, including zinc, magnesium, copper, iron and manganese. It’s understandable why people love it who know it’s health values, but I always just loved it because it’s goooooooood eating. 
I especially love Mexican Street Corn…yummmmmy
Which is why it’s often been a big part of livestock feed.
Well, I would have said that corn is widely used because it is a relatively lower-priced concentrate, not because it is a higher-nutrient feed. The corn is used as a cheaper source of energy, and other more nutritious feeds (for example alfalfa) are added to the ration to make up what the corn lacks. I hear that the big feedlots run algorithms that determine the cheapest way to blend up a sufficiently nutritious ration, depending on the current prices (including shipping) of numerous possible ingredients.
Traditional cultures have raised corn and beans together for good nutrition plus the beans fix nitrogen into the soil (corn is a heavy feeder in the garden).
@bkh
Livestock nutritionist here! Yes, big feedlots do pinch every penny, and your description of their ration balancing is correct. Corn has lots of advantages in addition to high energy content (depending on type, ~70-75% starch). It’s a C-4 grass, plant-physiology-wise, which makes it very efficient, fast growing, high yielding and well adapted to hot environments. It is low in lysine, the first limiting amino acid for most non-ruminants, and therefore often has soybean meal (by-product of producing soybean oil for human vegetable oil use) or as you mentioned, alfalfa meal, mixed with it to “balance” the amino acid content of the diet. @CatLady Hence the corn and bean combination.
… and squash. “The three sisters.”
It’s corn on the cob season again so I am reviving this thread from last year. I found that @Beacher’s way to estimate carbs works quite well. Last night’s ear was very glycemic, tonight’s not quite as much and then my BG dropped enough that I ate a couple of little Loacker hazelnut wafer cookies. 
@CatLady My wife “loves” corn on the cob this time of year. She’s given up on a lot of foods for my sake (against my wishes and comments), but COC is NOT one of them! She’s like Sherman Potter of Mash fame, “I’m just gonna bend that stalk over into the pot of boiling water”, drench it in butter, and sink her teeth in! Have to say I still indulge a bit too once in a while!
