If any body wants to maintain its body shape or he/she wants to develop muscles than protein is advised by professionals to them. Common theory is to eat 0.8g of protein per kg of body weight so that protein can become part of your blood and can help in muscle synthesis. According to some other theories 1 or 1.2 gm of protein should be consumed for better results.
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It is always good to eat more protein diet to build muscles, but what is the limit to for eating protein? there are some health problem related to intake of large amount of protein. It can accelerate kidney damage or they can also develop a stone in kidney if taken for longer period of time. Lever can also get damaged with the intake of protein. Protein induced acidity can also health of out bones.
Some time more protein could have negative impacts on your efforts to achieve your goals. If you are trying to loose weight than you could end up having more fats on your body. If you are trying to gain weight than too much protein could become hard to digest.