discussion for Nutritional class

this question is (discussion - just answer 5 sentences and please Acknowledge your classmates' posts. 

• (Build upon these posts by providing additional details, statistics, ideas, perspectives, or links to interesting, relevant articles. 
• Conclude with a question or new idea to further stimulate the discussion.)

q1/If all macronutrients and micronutrients are vital to human health and are provided by nature, why do we need nutritional guidelines such as the USDA Food Pyramid? Further, have these recommendations been more hurtful or helpful to Americans’ health?