How do you estimate emissions from food?

Food is the hardest part, because emissions vary hugely between farms. The largest global study, by Poore and Nemecek (Science, 2018), shown by Our World in Data, gives these global average figures:

Food	kg CO2e per kg of product
Beef (beef herd)	99.48
Lamb and mutton	39.72
Cheese	23.88
Farmed fish	13.63
Poultry meat	9.87
Eggs	4.67
Rice	4.45
Milk	3.15
Other pulses	1.79
Wheat and rye	1.57
Potatoes	0.46

These are global averages, not Indian values. Rice paddies and dairy cattle produce methane, so rice and milk can matter a lot in Indian diets. Our World in Data notes that transport is usually less than 10% of a food's emissions, so what you eat matters more than how far it travelled.