Have you ever looked on the back of a can and read the Serving Size details?
Go grab a few cans of commercially can foods from your pantry. I'll wait.
Now, look at the back of that can.
I have a can of green beans here.
It says on the back "4 Servings per can, Serving Size 1/4 cup.
I opened my can (don't worry, they won't go to waste)
I divided it into 4 servings.
17 green beans per serving is what it worked out to.
Now, I raised mainly boys. If I had put 17 green beans on one of my kids plates (especially when they were teenagers), they would have accused me of trying to starve them!
A can of collard greens looks a bit better.
"Serving size 3/4 cup"
Still...doesn't look like much when on a plate.
There's a reason that QUART jars became the standard for canning. There was enough in a quart jar to feed a family.
If it is just you, maybe those itty-bitty commercially canned foods will be fine. They will even work for a couple.
But for an actual-to-goodness family, you need to open two cans or use self canned foods in quart jars.
Back to serving sizes...
Who designates HOW MUCH is a serving size?
I guess, in the US, the Dept. of Agriculture or the Food and Drug Administration.
According to all the mandates, recommendations, etc. that are handed down, you need 4 to 5 "servings" of fruit and vegetables a day.
Sounds like a massive amount UNTIL you look at what is considered a "serving".
4 strawberries or a half a banana is considered a "serving".
1/2 cup of milk. 1 slice of bread. 2 or 3 ounces of meat. 1 carrot. 1 tablespoon mayo. 1/2 cup green beans. 1 slice of that pre-processed cheese *food*. 1/2 an apple.
To me, a serving size is much different. I don't know about you, but I generally finish a whole apple. My sandwiches include TWO slices of bread.
What I am saying here is that *official* recommendations are NOT "one size fits all".
If you are dieting you may want/need less. If you are undergoing physical or medical stresses, you may need/want more of a specific food.
Or you just may want to sit down and scarf down a WHOLE banana!