Being so conscious about health and nutrition, people generally commit these common nutrition mistakes. So keep a note of the following and try to avoid: Avoiding all forms of fats, some fats are necessary for our body in certain amount. So, don't completely strike out fats from your diet. Too much reliance on food supplements. Its universal fact that food supplements can not replace natural nutrients so this is the general major mistake people make. Over consumption of protein, it could lead to toxicity in body.