Analysis of test questions: Reasonable nutrition refers to comprehensive and balanced nutrition. "Comprehensive" refers to the complete intake of nutrients; "Balance" means that the intake of various nutrients should be appropriate and balanced with the needs of the body. In order to achieve reasonable nutrition, five kinds of food should be balanced according to the "balanced diet pagoda" to avoid malnutrition and overnutrition. Grains are rich in starch and other sugars, and are the most important energy-supplying substances. The energy consumed by human beings in various life activities mainly comes from sugar, with the most intake every day, followed by vegetables and fruits, and the least intake is fat.