This is okay with nuts and potato chips and if I compare the Nouveau Cuisine recipes some people will actually pay large sums of money for these amounts on a plate.
From personal experience at our meat store, catering and also serving food at dinners at our house, these serving sizes are a joke and any normally physically active person probably could not even survive on these servings.
When I was young, working in the meat business, a two pound Sirloin Steak with two nice sized baked potatoes, a bowl of salad and one quart of full fat milk was a serving size for me and at that point in my life I did not gain an ounce of weight!
On the other hand, one of my more affluent customers who I knew from my involvement in an organization came to me for advise on quantities for an Oktoberfest: 20 people (mixed couples). I suggested 1 Knockwurst (about 4 oz each, which is a serving size) per person and to figure 2 for the men. So a total of 30 Knockwursts, 1/4 pound of potato salad per and 1/4 pound of our precooked Bavarian Sauerkraut, so a total of 30 sausages, 5# potato salad and 5# of Sauerkraut.
She finally decided on 15 sausages and 3# each of the potato salad and sauerkraut as the only food served. I actually said to her that it was only good that I was not invited to that party.
Now the variable here is male and female eating habits, with women usually eating smaller portions than men, with that in mind the amounts served should be enough that none of your guests will leave your dinner table hungry. I would feel embarrassed if we would ever run out of food during any party at our house which includes a meal.
Here I have to quote an old German saying:
Das Schönste am Feste sind nicht die Gäste, sondern die Reste” (The most beautiful thing about a festival are not the guests, but the leftovers!)
Now to the actual serving sizes.
In the industry we always considered half a pound of meat per person in cuts without a bone and one pound on bone-in cuts (spareribs would be actually higher as we figured a whole three pound slab as enough for two people). These are pre-cooked weights.
We always figured at least one nice size potato per person and if you mash them you would have to increase the amount as we noticed that our guests always ate more of them.
We consider one cup of raw rice to give you 4 servings
About 2 to 3 ounces of dry pasta per serving
We suggest about a 1/4 pound per person.
and now for
Eat all what you can stuff in, you can always go on a diet tomorrow. LoL
Now these amounts should be sufficient so that you do not run out of food when entertaining guests.
The U.S. Food and Drug Administration has some pretty comprehensive webpages on the subject “Nutrition Facts Label Programs and Materials” (click on title to go there).
They also have a 2¾ minute video about it.