Alternative Protein Production: Counting The Calories

This report from the Humane Party seeks to quantify and compare the calories and protein produced by farmed animals and plants in the US. The animal products used in this analysis are: meat from cows, chickens, turkeys, and pigs, milk from cows, and eggs from chickens. These products represent the bulk of the output from terrestrial US animal agriculture; fish and other aquatic animals were not included. The plants examined in this study are: soybeans, dry beans (navy or black), dry peas, lentils, spring and winter wheat, and sunflower seeds. These products were chosen because the researchers deemed them to be the closest replacements for animal products besides processed mock meats. These crops also had reasonably large acreage in the US, compared to similar crops like pumpkin seeds, garbanzo beans, and quinoa.

The researchers found that plants generally outperformed animals in terms of calories-per-acre and protein-per-acre. Soybeans topped the list with a monumental 6.2 million calories and 500,000 grams of protein per acre. Dry peas, dry beans, wheat, lentils, and sunflower seeds all performed similarly, ranging from 150,000 to 210,000 grams of protein and 2.1 to 4.3 million calories per acre. Lentils provided the least calories per acre of all the plants, with 2.1 million, while sunflowers were the worst-performing in terms of protein, providing only 150,000 grams per acre.

Animals varied widely in their output per acre, but generally performed worse than plants. Meat from cows was the least-efficient food source: one acre provides only 8,000 grams of protein and 89,000 calories. Even the lowest-performing plant product – sunflower seeds – produced over 1800% more protein per acre than did cows. Milk was similarly inefficient, producing 50,000 grams of protein and 1 million calories on a single acre. The most efficient animal product was chicken meat, providing 163,000 grams of protein and 1.4 million calories per acre. This outperforms lentils, wheat, and sunflower seeds in protein output, but is lower than all plants in terms of calories. The least-productive plant food – lentils – still provided 2500% the calories that cows did.

The evidence in this report is clear: plants are a much more efficient source of protein and calories in terms of land use. Only one animal product was able to best any plant product in protein, and none were able to do so in terms of calories. If we are to maximize our agricultural output to feed a growing nation and a growing world, we must shift to a plant-based diet. Relying on animal products for nutrition – especially cows – is going to become less and less responsible in the future. This is but one reason why shifting to a plant-based diet is beneficial, but it is important. Moreover, this conclusion doesn’t rely on any ethical arguments or debates about climate change: plants are simply more efficient at producing food than are virtually all terrestrial animals.