This is an interesting proverb dealing with God's provision for the righteous. It involves both a promise for the righteous in regard to having enough food in addition to another apsect dealing with how the rightseous have an appetite that can be satisfied. The second has more to do with the heart than it does with food.
When we look at this from the viewpoint of food and the filling of a man's stomach we see that God promises that we will have enough to satisfy our appetite. In a psalm David said that he was young and now he is old, yet he has never seen the righteous forsaken or their children begging bread. God has blessed me with the honor of knowing a couple from Latvia who actually walked from Latvia to Eastern Europe during WWII. They did this while war was raging between the Germans and the Russians. They actually were trapped in the middle of a battlefield for a couple of weeks. During this time they had no food whatsoever. Yet for two solid weeks God would have various members of the family find hot baked bread in the middle of a battlefield. This was enough to satisfy their appetite each day. Truly God will provide for the righteous.
The stomach of the wicked is in need though. This is often the case in lands where God is rejected and false gods are worshipped instead. In India there is plenty of food for the entire population, but many are hungry because they will not eat cows for fear that it is a relative who was reincarnated. Some even refuse to kill rats that ravage their wheat and corn supplies for fear that they will have bad karma from killing a person reincarnated. Thus even though they have plenty of food each harvest, many stomachs are in need. A false view of God leads to religious views that harm a society.
There is another view of this proverb though that I also want to address. This is the fact of our inner appetites. Ecclesiastes says that God has placed eternity in our hearts. That is why there is an insatiable appetite within mankind for something to fill an inner need. Some spend their whole lives searchin in vain for this inner satisfaction because they seek it apart from Jesus Christ. It is only in Him that this void can be filled. So we see that this proverb is true once again - that the righteous (those who came to be righteous through what Jesus Christ did on the cross and by His resurrection) are filled and satisfied. The wicked - continue to want and need and feel like something is missing. My hope for each of you is that you will find your "eternal void" within filled by turning to Jesus Christ to find the salvation and the righteousness that will allow you to be satisifed and filled.