The extent to which someone chooses to stock perishable goods for emergency situations is up to him or her. Since a food or water shortage could occur without advance notice, due to upsets in the weather or logistical problems caused by human error, it is always wise to have certain things set back for such circumstances. In Proverbs 6:6-8, God points to the ant as our example, commending her for properly preparing, during the summer months, for the long winter ahead.
However, for a person to think that he could preserve his life during the coming famine and tribulation, by stockpiling foodstuffs, would be foolish. Christ showed in Matthew 24:21-23 that world conditions would be so bad during the Great Tribulation, that, if God did not intervene, all of mankind would be destroyed. Christians should not put faith in any stored provisions, but rather in God (II Cor. 5:7; Heb. 11:6; Hab. 2:4).
God promises a place of safety to all His truly faithful servants during this terrible three-and-a-half year period.