God provides food for all?

In last weeks parsha, עקב, we have the mitzva of bentching after eating. In the first beracha we say:

הַזָּן אֶת הָעוֹלָם כֻּלּוֹ בְּטוּבוֹ בְּחֵן בְּחֶסֶד וּבְרַחֲמִים, הוּא נֹתֵן לֶחֶם לְכָל־בָּשָׂר כִּי לְעוֹלָם חַסְדּוֹ וּבְטוּבוֹ הַגָּדוֹל תָּמִיד לֹא חָסַר לָנוּ וְאַל יֶחְסַר לָנוּ מָזוֹן (תָּמִיד) לְעוֹלָם וָעֶד בַּעֲבוּר שְׁמוֹ הַגָּדוֹל כִּי הוּא אֵל זָן וּמְפַרְנֵס לַכֹּל וּמֵטִיב לַכֹּל וּמֵכִין מָזוֹן לְכָל־בְּרִיּוֹתָיו אֲשֶׁר בָּרָא

 who provides food for the entire world
in his goodness, with grace, kindness, and mercy.
He supplies bread for all living beings,
for His kindness is everlasting.
Because of His great goodness,
we have never lacked food, nor will we ever lack it
on account of His great name
since He is God who feeds and provides for all
and is good to all and who supplies food
for all His creatures which He brought into being.
(Translation taken from aish.com)

How do we reconcile this with the many famines that occurred throughout history and still occur today? How can we state that we have never lacked food when we have? How can we say that god feeds and provides for all when there are starving people in the world?