ToddyHill said:
Just taking a guess, having worked in corporate at two national restaurant chains.
The food cost for a serving typically runs around 30%. So, if the total food cost is $3.50 the menu price would be around $11.69. The 'return to net' would be the difference between the price less the cost, or $8.19.
Now double the size of the portion. Food cost is $7, so the cost stays at 30%, but the menu price of $23.38 doubles the 'return to net.'
Not saying that's why portions are big, but in a competitive industry the return on net is a big deal. Just my opinion.
to add onto this.. the larger portion takes same amount of time to put on a plate that the small one does, so your labor cost remains the same.
In other words, putting a 4oz burger on a bun with some toppings and 2oz of fries is the same labor cost as putting an 8oz burger on a bun with some toppings and 4oz fries. So this return on net is increased with a larger portion.
Scale it down to an exaggerated level to see the point. It's why 'flights' of beer are much more expensive per oz than a pint. It's more labor cost, and more dishes to clean.
Although to play devil's advocate, economies of scale does come into play with larger portions. I would expect to pay less per oz for a 16 oz beer than two 8oz half pours. Or less per oz for the 16 oz steak option compared to the 8oz option.