Principle purpose of this article is to explain Symptoms of Protein Deficiency. Even with many protein sources available, some people experience protein deficiency symptoms because of lack of protein consumption. Severely restrictive diets, deficit of knowledge about nutrients, and in some cases poverty can contribute to help protein deficiency. Our culture is now obsessed with consuming protein for lean muscle gain and for weight loss. This means few people are skimping on the actual stuff but, despite our own national preoccupation with necessary protein, some of us are still vulnerable to protein deficiency-namely vegetarians or folks who tend to under-eat.