For growth to occur, anabolism should be greater than catabolism:

• Anabolism: The building-up process of synthesis. e.g DNA synthesis, protein synthesis
• Catabolism: The destructive process of breaking down molecules. e.g respiration 

When anabolism is greater than catabolism, the organism is synthesizing more new material than it is breaking down. This results in growth, which is an irreversible increase in the size, volume, or weight of the body.