Growth is a continuous process. There's no limit to growth we can attain both physically and mentally. As christians, beyond just striving to grow physically, financially and otherwise we should also strife to grow spiritually. There are many ways to grow spiritually and one of them has to do with the constant study of God's Word. Just as the food we consume is nutritional value and nourishing to our bodies so is the word of God nourishing to our spirit.
Jeremiah 15:16 - Thy words were found, and I did eat them; and thy word was unto me the joy and rejoicing of mine heart: for I am called by thy name, O LORD God of hosts.
We can see in the reading above the joy that came to Jeremiah as a result of eating the Word of God, in order words consuming God's Word. The same way we don't place a number of times that our body should receive nourishment is the same way we shouldn't assign a number of times we should nourish our spirits with the Word of God.
Matthew 4:4 - But he answered and said, It is written, Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God.
Part of what gets us going in life especially when we are faced with storms and difficult times is the Word of God. But this is only benefiting to those who hold unto the Word of God closely and the only way it can be achieved is through the constant study of God's Word.