Beef vs Lentils
Beef is the single most emission-intensive food in common use: ruminant methane, feed production and pasture expansion stack on top of each other. Lentils fix their own nitrogen, need no feed conversion step, and match beef almost gram-for-gram on protein.
Per per kg of food
Greenhouse gaseskg CO₂e / kg
Beef
99.5
Lentils
0.9
Land usem² / kg
Beef
326
Lentils
3.4
Freshwater withdrawalL / kg
Beef
1451
Lentils
1250
Proteing / 100 g
Beef
26
Lentils
25
Source: Poore & Nemecek (2018), Science · Our World in Data · USDA FoodData Central
Verdict
Lentils deliver comparable protein for roughly 1% of the climate cost.
Questions people ask
Is grass-fed beef better?
On climate, usually not. Grass-fed cattle grow slower and emit methane for longer, and they need far more land per kilogram.
Do lentils provide complete protein?
Lentils are lower in methionine, but eaten with grains across a day the amino acid profile is complete.