A balanced diet
Having a balanced diet means eating in such a way that our bodies are able to obtain all the nutrients they need for...
+ to carry out the most basic tasks, like breathing
+ maintain and renew our cellular tissue
+ to grow more cells
+ think, move, work, etc.
Previous lines, it might seem that all need the same things, but in real life there is no recipe "for all ages". We are all different and also our needs.