The young lions do lack, and suffer hunger. Some suppose the "young lions" here to represent the proud and violent, as in Job 4:10. But it is simpler to take the present passage literally. In God's animal creation even the strongest suffer want for a time, and have no remedy; his human creatures need never be in want, since they that seek the Lord shall not want any good thing.
It is open to them to "seek the Lord" at any time.