First, did you realize that popcorn was enjoyed by South American cultures thousands of years ago? Popcorn was not invented for Thanksgiving by American colonists :) To ancient peoples, corn was a critical part of daily life. There was even a God of Corn. His headdress was a wreath of popcorn. As you might imagine, a culture that worshiped corn learned how to make corn meal, corn bread, corn muffins, popcorn, and anything else you could possibly do with corn. There was even corn soup, popcorn beer, and more.
The reason corn pops is that there is about 14% water inside the dried corn kernel. The kernel is a "corn seed" that has everything a new corn plant needs to grow - starch, sugar, and water. When you heat that kernel up, the water turns into steam and POP - it explodes.
But on to nutrition. Corn isn't exactly a powerhouse of nutrition. For hard-working cultures, it provided easy energy for long days of farming. In modern times, the most we do is walk to the fridge to "hunt for food". So when you look at popcorn, it isn't great. If you're lucky it has around 2% Vitamin C and 6% Iron.
Carb counts vary from brand to brand but right now I'm looking at an Orville Redenbacher nutrition label for their microwave popcorn. It has a whopping 17g of carbs, with only 3g of those being fiber. And that's for 2 tbsp of kernels - i.e. not the entire bag! Really, a kernel of popcorn is a little bundle of energy, to help a seed grow. To humans that don't need more energy, that'll be stored as fat quite nicely.
Most people do not eat a a small portion of a bag of popcorn. They eat the entire bag. That gets you into the range of 50g-100g depending on how the popcorn is flavored. For example, in this Orville example there are 2.5 servings per bag. Since each serving has 14g net carbs, that is 35g of net carbs per bag you're eating. With pretty much no nutrition going into you.
Sure it's better than eating a pile of chocolate bars - but you should be eating broccoli and other healthy snacks instead! Your body needs that nutrition.
If you go into a movie theater it's even worse - even the smallest sized bags are full of more than one serving of popcorn. Usually we add on butter-flavored goop to it, and tons of salt. That means that not only are we consuming a ton of carbs, but we're adding saturated fats to the blend.
That all being said, I like popcorn. It's easy to make, it's hot, it smells wonderful, and it's natural. Compared to the other artificial junk food on the market, at least with popcorn you're eating a normal vegetable. So if your choice was between sugar-filled candy bars or popcorn, I'd go for the popcorn. But if you actually had a bit more control over the situation, I'd go with nuts if you were in a salty mood - or with celery sticks if you were in a crunchy mood. With popcorn being loaded with carbs and having pretty much no nutrition, you are only harming yourself by putting these things into your mouth.
Raw Popcorn
I have gotten messages from people who eat "raw popcorn" (i.e. hard kernels with no butter or salt) and feel it is a health food. First, I know several people who have broken teeth doing this. One broke her tooth just recently. I'd really recommend against eating raw popcorn - a broken tooth is really painful. Also, corn is a naturally sweet vegetable. It has all that sugar and starch built into it so the corn plant can grow. It is a little powerhouse of energy. That's just not high on the "good to snack on" list!
Grain, Vegetable, or Fruit?
Is corn a vegetable, or is it really a grain or a fruit? All grains are part of the vegetable family - they get called "grains" when we take the dried seed and do something with it (grind it into flour, etc.). So if you let the corn dry out and then grind it into corn meal, then sure at that point it's a grain. but if you harvest the ear of corn when it's "ripe", then that's just like taking tomatoes off a tomato plant. In both cases you're taking the seed-holder off the plant to eat it. We call that a "vegetable".
If you want to be even more precise, in botanical terms these things are "fruits" because they are the seed-containing unit of the plant.
So corn gets to be three things at once!
Lisa Shea's Library of Low Carb Books
