There are thousands of proteins in the human body. They are constructed from amino acids. Humans can synthesis most requires amino acids but 9 of them must be obtained in the diet: histidine, leucine, lysine, isoleucine, methionine, trytophan, phenylalanine, threonine, valine.
Each of these is required for manufacturing different (though intersecting) sets of proteins. Each has a separate recommended daily intake. Because there is some redundancy in the functions of some of the proteins in the human body, the requirements are somewhat interactive: a deficiency in one AA can partly be made up for by excess intake in others, but a lack of any one of them will result in death.
2 to 3 months without protein will result in death.
The recommended intake for adults varies a bit with various factors but it’s broadly in the vicinity of 0.75 g per kg body mass. Different agencies give different numbers but it’s always somewhere around there. (Some sources prefer to give the figure of 1.2 g per kg lean body mass, since added a bunch of excess fat to a body doesn’t increase the protein requirement linearly. )
Protein deficiency in children has life long irreparable effects including stunted growth, incomplete brain development, and sensory and immune issues etc.In adults, the effects are often reversible, unless you’re dead I suppose. They include immune deficiency, poor recovery from fractures, muscle mass loss (duh), edema, fatigue and lethargy, loss of mental acuity (brain fog) and irritability, enlarged liver.
Protein deficiency is very rare in Australia, where most people consume protein far beyond RDI.
Even among Australian vegans (see below), average protein intake was 81 g per day for men and 54 g per day for women: certainly a bit below the averages for Australian omnomnomnivores but still above RDI.
https://www.mja.com.au/journal/2013/199/4/protein-and-vegetarian-diets
If you’re a dude of average Australian height with moderate activity your requirement might be around 68 g and it is surprisingly easy to get this on a vegan diet. Morning cup of muesli 10 g, with a cup of soy milk on it 3 g. Lunchtime bowl of chili beans, 18 g. Serving of fried tempeh and vegetables 27 g. That leaves 10 g to be obtained from any drinks or fruit/veg, snacks, sides etc. There’s a bit of protein in all foods.
——
Friend roughbarked has said:
“I’m sure I’ve worked harder than trans and I still wouldn’t have consumed 60gm per day again for many decades.”
I think you might be underestimating your protein intake. If it is not too much of an intrusion, could you give us a rough accounting of your daily eats and drinks?