From the Tanya (Iggeret HaKodesh, beginning of Epistle 1)

פותחין בברכה, לברך ולהודות לה׳ כי טוב.  שמועה טובה שמעה ותחי נפשי. אין טוב אלא תורה

We begin with a benediction, to bless and to give thanks to G‑d, for He is good. My soul has heard and been revived by good tidings —  and “good” signifies Torah, as our Sages state in Tractate Avot.

 

*Bless for Life*

When we eat food, we wish that our body absorb the life energy in it and dispose of the ‘material’ so we won’t get heavier with every food item we eat.

We purchase food from vendors, but its vitality is from Hashem. That is why we need to bless Hashem for the food we eat, even though we paid full price for it.

We pay for the material and the delivery process from the source to our mouth. BUT without the life energy in the food, it is all death (disease, cancer, etc.). Therefore we don’t eat ‘dead’ food. We prefer fresh, natural (organic) that we process ourselves without external energies attached to it.

We learn to bless the food, and if we don’t know how to bless, we look at the food with the knowledge that the life energy in it is from Hashem and give thanks to him before letting it into our body.