Let's calculate the energy consumption of 2000 kilocalories a day.
2000 calories is about the daily energy consumption (basal metabolism+daily consumption) of an adult woman weighing about 55KG.
Consumption of 2000 calories per day requires 72 grams of protein.
How much is 72 grams of protein? There are data to calculate.
1000ml milk is about 30g.
100g lean beef is about 22g.
100g chicken breast = 20g or so.
100g egg = about 13g.
100g shrimp = 20g or so.
In other words, how much protein does a 55KG woman eat a day?
About 1 l milk+100g lean beef +4 eggs.
There is also an easy-to-calculate daily protein intake:
Female 1KG body weight, daily 1~ 1.2 g protein.
Male 1KG body weight, daily 1.2~ 1.5 g protein.
To lose weight, you need 1.5g protein and 1KG body weight.
That's about it.