First of all...the restaurent exists...same as your home does...so, I don't see how the power consumption of the restaurent really figures into the equation...and so the final reason stated, that only 35% goes into the food, is irrelevant...if the question was "to have restaurents or not" then it might matter...but the fact that the restaurent has to have light and heat, shouldn't figure into your personal decision...and besides, kitches are very efficient in producing food....which uses more energy, a thousand kitchens producing one meal each or a restaurent making a thousand meals...
So...
It's almost certain that cooking one extra lo mein dish uses less additional power (if any - after all the deep frier, burners etc...are all running anyway) than a home user turning on their stove/oven etc...(the argument here is that the more people order, the more energy efficient the restaurent becomes as it produces more food with the same energy use)
The restaurent is going to wash their cooking gear anyway (the lo mein guy doesn't wash the skillet after every dish), whereas you now have to use power and resources you otherwise wouldn't.
The ingredients bought from the supermarket came in packaging...probably less than what you'd get from the restaurent (i.e. noodles are smaller and packed more tightly uncooked than cooked) but is not any likelier to be recyclable.
The questions that really matter are:
- How does the lo mein get to you? If you're ordering from a place at the edge of their delivery zone and having it driven over or walking over to pick it up makes a huge difference.
- Do you have lo mein ingredients on hand anyway, or did you have to buy things that will likely not get fully used before getting tossed. I think this is very under-rated as a question for those of us who either live alone (like I do) or like to experiment in cooking.
As a single guy, I don't have a lot of spices on hand because I don't want to buy $5 worth of tarragon and need a pinch for that one dish (and toss it six months later when its lost its flavour). I don't buy sour cream unless I play on making sour cream heavy dishes before it goes bad.
So...there is a huge differrence between a single guy who makes lo mein twice a week but doesn't feel like bothering and walks over to a pick-up joint to go get some OR a single guy buying seventeen ingredients he otherwise doesn't use to make lo mein one time OR a single guy who decides to order lo mein from the farthest place that will still deliver, in the middle of a snow storm lets it get cold and then reheats it in the microwave and then eats it on the balcony over an oil drum burning phone books for heat.
The point is...a lot of details that go into the equation matter...on average, I'd tend to agree that delivery isn't as good as cooking....but I don't think they are far apart and the personal answer hinges on how it gets to your house, what ingredients you normally have on hand etc..etc...
