Benchmark 6C
The Human Organism: Basic Functions
Grades 3-5, page 136

From food, people obtain energy and materials for body repair and growth. The undigestible parts of food are eliminated.

NSES Content Standard F 
Science in Personal and Social Perspectives: Personal health
Grades 5-8, page 168
Food provides energy and nutrients for growth and development. Nutrition requirements vary with body weight, age, sex, activity, and body functioning.