וַיֹּאמֶר אֱלֹהִים הִנֵּה נָתַתִּי לָכֶם אֶת כָּל עֵשֶׂב זֹרֵעַ זֶרַע אֲשֶׁר עַל פְּנֵי כָל הָאָרֶץ וְאֶת כָּל הָעֵץ אֲשֶׁר בּוֹ פְרִי עֵץ זֹרֵעַ זָרַע לָכֶם יִהְיֶה לְאָכְלָה
And God said: ‘Behold, I have given you every herb yielding seed, which is upon the face of all the earth, and every tree, in which is the fruit of a tree yielding seed–to you it shall be for food; (Bereishis 1:29)
The Vilna Gaon asks “What is the ma’amar which Chazal attribute to this pasuk?” (a ma’amar means an utterance of Hashem’s name which causes creation). “This pasuk seems merely to summarize all of the creation until now.” And he answers “It is true that there was food in existence beforehand, but it was not yet ready for human consumption. With the utterance of ‘l’chem yiheye l’achlam’, it became a usable food item.”
We can learn from this that even though we may have an abundance of usable things, they do not become useful in a real sense until there is a ma’amar from Hashem. It seems to me that the utterance of a brocha will release the potential in the foods that we eat so that they can genuinely be sustaining. So too, when we acknowledge Hakadosh Baruch Hu’s involvement in all that we do, when we say “Im Yirtzeh Hashem” or “Be’ezras Hashem” by including Hakadosh Baruch Hu we can access the potential of the brocho that Hashem has given us.