God is faithful to His promises to provide for His faithful followers. David could testify that he had never seen the Lord forsake the righteous nor had he observed any of their descendants unable to get food. God promised the Israelites that He would bless the descendants of those who obeyed Him ( Deuteronomy 7:9). [source][source][source]
It is possible to account for the fact that some believers have starved to death. They may not have followed the Lord faithfully, or they may have been part of a larger group, even all humanity, that did not follow Him faithfully and was under His judgment (cf. Psalm 37:4). David did not say the righteous never starve to death, only that he had never seen any that did. His point was that God takes care of the righteous. [source][source][source]