The human body needs protein. Proteins carry out countless functions inside cells and they are vital for the growth, repair and maintenance of muscles, bones and skin. And with food companies rolling out high-protein versions of a huge range of foods, including milkshakes and granola bars — and even pancakes and popcorn — you might be tempted to think you need to add more to your diet. But nutritionists say that if you are getting enough food, you are probably getting enough protein. to is...