[toasterlovin]

Look, calories per $ is a crude metric that I would not put forward as useful for food items which are within 2x of each other in terms of calories per $. But when you're talking about a 12x difference, I think you have to engage in serious denial to dismiss it.

> You mention in passing how you'd need to grow agriculture to feed animals anyway, and then completely ignore that fact through the rest of your writing.

I'm not sure what you think I should have addressed about this, but I have had people try to claim that meat cannot possibly be easier on the environment than plants, since animals consume plants and there is energy loss in that process, so I'll assume that's your objection. And the answer is that animals are fed plants which provide a lot of calories per $. If you were to base your diet on those plants (grains, essentially), then, yes, it would be better for the environment than eating meat. But I was specifically pointing out that there are classes of plants (leafy greens and berries) which are worse for the environment than some meat (chicken). There are also classes of meat (red meat; 50-400 calories per $) that are worse than certain classes of plants (potatoes, grains, and nut & vegetable oils; 800-3000 calories per $).

[trentlott]

The argument is thermodynamic: meat will never provide more calories than it requires.

[TheCoelacanth]

In the case of leafy greens, most of the energy will be tied up in cellulose that will pass straight though a human digestive system undigested.

Any model that treats a human body as a perfectly efficient bomb calorimeter will produce such inaccurate results as to be virtually useless.

[toasterlovin]

Plants, as a class, have a cost per calorie with a 60x range (from about 50 to 3000 calories per $). Animals are fed with plants at the higher end of that range. If you replace your meat consumption with plants at the lower end of that scale, it does not result in lower resource consumption.