Kwashiorkor is the condition of not enough protein while actually getting "enough" total calories. What's more, low overall protein intake actually increase your need for essential aminos, due to the body synthesizing non-essentials from its supply of essentials.

There are also serious health effects (eventually leading to death) associated with deficiencies in specific essential aminos. Lysine deficiency is one. You only need 28mg a day but if you are eating mostly wheat it can happen.[1] If you are lysine deficient it comes with its own disorders and it also leads to micronutrient deficiency.

[1]http://www.pnas.org/content/101/22/8285.long