Why is this a problem? Animals also produce higher quality protein with higher bioavailability, have a better amino acid profile that better suits what humans require, and provide nutrients that people cannot get from plants.
That's on top of the fact that a lot of those plant calories aren't even consumable by humans.
It's a problem because of the aforementioned disproportionate energy consumption.
> "Animals also produce higher quality protein with higher bioavailability"
Hey look, you don't have to pitch me on meat -- I'm basically a carnivore. Personal preferences don't change the underlying engineering dynamics.
> "and provide nutrients that people cannot get from plants."
I love meat and I'll defend it as stridently as anyone, but this just isn't a rational argument. I want meat in my diet, but I do not require it to live. There are many ways to achieve a balanced diet either with other animal products, or without meat altogether.
The really weird thing about diet is that many (most?) of calories a typical American consumes are in excess of a healthy amount and are hurting us rather than helping us. It's a very strange dynamic, because the vast majority of Americans suffer from excess nutrition -- not malnutrition.
These excesses not only hurt our health, they harm the environment. Fat people create far more greenhouse gasses per capita than thin people. I eat meat, but I also eat healthy portions -- which puts me far ahead of most people regardless of their diet in terms of the resulting carbon footprint.
Taurine, Creatine, Carnosine, and B12 are not found in significant amounts in plants. Heme Iron is much more bioavailable than Plant Iron or Iron supplements. Plant-based diets can also inhibit the absorption of many more nutrients, including Iron and B12. You cannot get the right type of omega-3 fatty acids through a normal plant-based diet, either, you must supplement it with an algae-based supplement.
In fact, a lot of nutrients that are abundant in meat and readily absorbed and processed by our bodies probably needs to be supplemented with a pill to get enough of it on a vegan diet. Choline can be found in plenty of vegetables, but are you actually getting enough of it? Incorporating meat into the diet makes it very easy to get enough of many nutrients that our body needs without having to take a half dozen supplements.
That doesn't even get into how a plant-based diet can negatively affect gut health and the composition of plants can inhibit nutrient activity and absorption. Nor does it get into how these diets can negatively affect children, either through the quality of nutrition derived from their mother's breast milk or from adhering to a plant-based diet in general.
I agree, meat calories are higher quality for a variety of reasons -- you don't need to argue this point to me.
My point is that these reasons are not essential reasons. You can survive without Taurine, Creatine, Carnosine because they are all synthesized by the body. Is it preferable to supplement with them in a diet? Yes. Are there more than a billion vegetarians on earth who don't supplement these? Also yes.
We can and should accept both of these facts:
1) Meat is a better calorie source.
2) Meat is less efficient in terms of energy consumption and this is a problem.
You can't disprove #2 by arguing about #1.
Yes there are some people who think that the best way to save the planet is to drink as much almond milk as possible. But that is not the strongest form of the argument.
You need to produce much more plants to feed the animal first instead of directly feeding you. So to stay on topic (unlike your "quality") this process uses more fossil fuels.
Yes, but in the case of grazing, it's plant material we cannot eat. That's called nutrient recycling because it converts what cannot be processed by humans into something that is.
In grain diets, a lot of it is produced specifically to feed livestock. This probably at least in part due to the significant subsidies on corn in the United States. Ending corn subsidies would probably be beneficial to American diet both in it'd raise the price of meats and increase the price on HFCS and other corn product.
With that being said, agricultural byproduct can be fed to livestock which can help close nutrient loops. Things like stalks, leaves, husks. Also milling byproducts like wheat and rice bran. soybean and canola meal from oil production. Peels and pulp that are produced from production of juice and other fruit products can be used.
There's a lot of ways to shore up inefficiencies in producing livestock and other agriculture that can help make it more sustainable than it currently is.
> So to stay on topic (unlike your "quality") this process uses more fossil fuels.
Quality is part of the topic because the quality of nutrients is the utility that meat offers and it's from that we need to make judgements on whether or not it's worth producing.
My argument is obviously yes, the increased cost in terms of carbon footprint is worthwhile because meat is such a great source of nutrients that naturally aligns with the nutritional needs of humans in a way that is difficult to do with a solely plant-based diet. There's also not wholly understood benefits of meat, probably because it's become the new boogeyman, like fat was made out to be in the 20th century.
