The question I get asked the most is what is the most important dietary advice I can give. People say to me, "Tell me what I should eat". If I had to pick only one message to tell the world about healthy eating it would be to CHOOSE WHOLE FOODS. When whole foods are selected we have the freedom to eat whatever we want and as much as we want. What is a whole food? I am not trying to market a grocery store. A whole food is a food that is closest to the way it is found in nature. For example, an apple is a whole food. Apple juice is not because it has the fiber removed from it. I am not saying that apple juice is bad, but juice intake needs to be monitored whereas apple intake does not. The more an item is processed, the less of a whole food it is. An apple is more of a whole food than homemade apple pie, but homemade apple pie is more of a whole food that MacDonald's apple pie.
The best description I have ever heard of a whole food is from a prior teacher. "If is serves no other purpose but to be eaten, then it is not a whole food." I will stick to the magnificent apple. An apple does not need us. It develops from a flower, it is a vessel for seeds, and those seeds hold the life of another apple tree. If an apple is not picked for consumption it will fall on the ground and eventually degrade back into the dirt to fertilize other plants or spread its seeds to start a new life. Now picture a twinkie. What if it is never eaten? No twinkie tree will grow, it will just sit there probably for a few thousand years.
Whole foods contain all the essential nutrients, they don't contribute to disease (depending on how they are grown but that's another story), they leave you feeling satisfied and when you eat whole foods your body knows when to stop eating. When was the last time your friend confessed to you that she failed her diet because she ate the whole box of oranges or half a gallon of brown rice with fresh herbs?
Next time you are shopping and don't know what to buy just think of how you would find the food in nature. Choose honey instead of refined sugar, whole oats instead of boxed cereal, or a potato instead of potato chips.