Hacker News Reader

Comment by notatoad | Hacker News Reader

the most convincing ethical argument i've heard for vegetarianism has nothing to do with the treatment/killing of animals, it is that eating vegetables is a much more efficient use of resources than eating meat. The amount of energy it takes to grow 500 Calories worth of broccoli is an order of magnitude less than the energy it takes to raise 500 Calories worth of beef. If all the resources currently used to raise animals for meat were used to grow vegetables instead, there would be plenty of food to spare for the whole planet. I'm curious as to the energy consumption it takes to grow synthetic meat.

(edit: to be clear, this argument has failed to sway me, i still love eating meat. It's just something interesting that i've heard before and thought was worth sharing. There may or may not be actual statistics to back this argument up.)

View on HN

500 calories of broccoli takes far more energy to produce than 500 calories of meat. Broccoli is bulky, it's mostly air & water and indigestible starch. It takes many pounds of broccoli to get 500 calories, whereas 500 calories of steak is only a few ounces. So unless that broccoli is hyper-local, transportation costs alone may make it worse. Even if it is hyper-local, I still suspect that broccoli is a worse way of converting solar energy into human energy than cows are.

Environmentalists usually compare meat to calorie dense vegetable sources, like grains & legumes. That's fair because it's impossible for a human to eat enough broccoli to stay alive -- it takes about the same amount of energy just to digest the broccoli as you get from it.

The "standard" metric for meat conversion is that it takes 12 pounds of wheat to make 1 pound of beef. But that's very misleading. Cows generally don't eat wheat. Naturally raised cows eat grass. Cows eating grass in midwestern North America is probably the closest we can get to its natural ecosystem, which used to be dominated by mammoths eating grass until they were killed off, then by bison eating grass until they were killed off. But humans can't eat grass. Cows have four stomachs and a rumination habit that ensure that it is efficiently digested.

Even feedlot cattle are much more efficient than the 12-1 metric would have you believe. The feed barley and feed corn varieties that are grown to feed cattle yield at rates 2-8 times better than the high-protein wheat varieties fed to humans. Not too mention the fact that when you feed corn to cattle you feed them the entire plant. Humans just eat the seeds.

Regardless of the broccoli vs wheat or what have you, something your parent said was striking--namely, that there would be enough food for the world. Here's the rub: We don't have a food shortage problem. We have a food distribution problem. I mean, eat whatever the hell you like--I don't particularly care, but understand that logistics is the major problem in third world food supplies today, not supply.

Is there an example food here other than broccoli that takes less energy but has more similar macros (protein, carbohydrates and fat) to beef or chicken? A major reason a lot of meat eaters choose to eat meat is the high percentage of calories from protein (in addition to the taste, obviously). Broccoli may be cheaper to produce 500 calories but those calories are mostly just carbs which most people get more than enough of.

Reply on news.ycombinator.com