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Comment by toasterlovin | Hacker News Reader

Meat vs. non-meat is not the right lens through which to judge the environmental impact of your diet. Cost per calorie is.

For instance, whole chickens provide about about 1200 calories/dollar, whereas leafy green vegetables all provide under 100 calories/dollar. That means there is a 12x difference in the amount of resources required per calorie provided. You can go on about the externalities of meat all you want, but a 12x difference almost certainly makes up for them.

So if you switch from eating lots of meat to eating lots of leafy green vegetables and berries, you probably aren't making much of a difference. The better heuristic to follow is to just pay attention to how much your food costs. Less money spent on food = lower environmental impact.

If you're interested, I go pretty deep down this rabbit hole here: http://www.thinkfundamental.org/why-kale-is-actually-terribl...

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What? No. This ignores subsidies, markup, shelf space, and that you probably shouldn't be going for the cheapest calorie per dollar anyway. Following your argument, we should all just eat pure sugar and butter.

I read your site, and it's all just FUD. 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. You don't cite any actual environmental numbers, pull some out of your ass, and then hand wave your way through your position.

> sugar and butter

GP is talking about environmental impact, not health.

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 $).

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

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.

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.

> Meat vs. non-meat is not the right lens through which to judge the environmental impact of your diet. Cost per calorie is.

Only if you pretend that the entire supply chain is an idealized free market without externalities, which is wrong in basically every possible way when it comes to food, everywhere in the world.

Yeah, my whole point is that when you have an order of magnitude difference in cost per calorie between two food items, that allows for an order of magnitude difference in externalities/subsidies/whatever.

If you meausred just calories per dollar you'd have everyone eating out of a communal 20 kilogram bucket of pure lard.

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