What food source contains all the essential amino acids and is the best source of protein? beans rice meat green leafy vegetables

can you plz give me the following

starvation is bad because your body needs nutrition and to deprive it of nutrition can cause problems with both health and fitness.

explanation:

it can make weight loss slow down over time, but it won't cause someone to gain weight depsite restricting calories. starvation causes weakness in the senses like thirst.