Dr Oz did a segment called Is It Better Raw or Cooked? You get more nutrients out of certain vegetables if you eat them raw, and others give you the most nutrition if you cook them lightly first. Doctor Oz spoke about whether it is best to eat carrots, onions and red pepper cooked or raw.
Dr Oz: Eat Carrots Cooked For More Nutrients
Dr Oz: Eat Red Peppers Raw For More Nutrients
Dr Oz said that red peppers are best if you eat them raw. The Vitamin C in peppers is water soluble, so it escapes into water the longer that you cook it.
Dr Oz: Eat Onions Cooked for More Nutrients
Dr Oz said that onions should be cooked, because they contain Flavonoids which are released when they are cooked. Flavonoids are an anti-inflammatory that help to protect against Heart Disease and Cancer. You should only cook onions for five minutes, otherwise you start to lose too many nutrients.