The Torah writes אני ההמעלה אתכם מארץ מצרים I am Hashem who elevated you from Egypt. Rashi comments that the Torah used here an unusual word "maalah" when the normal description is with the word .הוצאתיRashi comments that the word "maaleh" used in the passuk is to be interpreted as an "exceptional middah" and quality. Therefore the passuk is saying that because Yisrael are prohibited from eating "sheratzim" this places them above every nation. We have to understand why is this issur so outstanding and superior above any other mitzvah for which Hashem took us out from Mitzrayim?
The Yesod Vesshoresh Veavocah writes in the name of the Rambam that one's hashkafos and opinions are dependent upon "what" and the manner of how he eats. The reason is because his food consumption is ingested and immediately transformed into blood and cells thereby becoming an integral part of his body, producing energy and systems function. This is in contrast to other aveiros which defile the nefesh not the guf. As the saying goes YOU ARE WHAT YOU EAT.
This differentiation between the two is conveyed by Tosfos (Chullin 5b) The gemarah asks how is it possible that an Amorah ate something that was prohibited when it is known that Hashem protects even the animals of tzadikkim from not eating kosher such as we find by the donkey of Rabbe Pinchos Ben Yair where it never ate non tithed food. Surely Hashem must protect the tzadikim themselves that they should never falter to eat non kosher. On this statement of the gemarah Tosfos asks that we find cases of Tanaim who unintentionally committed worse aveiros such as killing someone by a wrong judgement or by transgressing Shabbos by mistake which are more severe than eating by mistake a non kosher food. Why then, asks Tosfos, would the gemarah assume that tzadikim won't falter by eating accidentally something not kosher?
Tosfos answers the difference I s that eating non kosher is worse than even an accidental Aveirah chamurah. The reason being because eating non kosher become part of one's blood and consequently sends a spiritual toxin in his entire being thereby compromising all his bechirah choices in ruchniyus. Even the Torah that he learns can become distorted.
To understand this even more let us examine the term used for kosher and non kosher foods. The Torah uses the term טמא וטהור. The word טמא is usually translated as impure. However the essential definition is אטום which means to be blocked and impenetrable. By eating a non permitted substance one blocks the light of Hashem from entering one's body. Vayikra 11,43 ולא תטמאו בהם ונטמתם בם that your mind and heart will be blocked from seeing the emes of Hashem (Yuma 39).
Note that these two words have the same pronunciation אתם אטם you and blockages. This connection just makes it even clearer the above statement You are what you eat. The Degel Machanei Efrayim brings a story of the Rambam who had an audience with individuals who were known to be yarei shamayim yet they were questioning a certain fundamental in emunah. The Rambam responded by saying it's time to check your shochet. They were perplexed at his answer. The Rambam then told them that he can't understand how a yarei shamayim like themselves can have such a question in emunah. The only possible explanation is that the shochet is not a yarei shamayim and you are eating טמא which effects the yashrus of your thinking.
The Peris Chadash Yoreh Deah 81,26 writes that the reason we find children who are chutzpedik and do not accept mussar is because they are consuming not kosher food.
We see from the above the severity of eating non kosher and the maalah of being strict in kashrus. For the manner by which one can sanctify and elevate his body is through kosher consumption for otherwise eating one bug in an unchecked leaf of lettuce will cause a blockage of Hashem's light from entering your physical body and elevating it constantly.
Recently I was in a popular restaurant and I ordered an egg on a bagel. When I went to get it I found it neatly placed in a box with the words CRAVE WORTHY. The word crave is very Impactful for it translates as a strong urgent or abnormal desire for a substance or activity, addiction. Therefore the usage of this title craveworthy denotes a stamp of approval that you are morally justified and proper to allow yourself to display "cravety" over this bagel and egg which we are serving you.
This novel title "crave worthy" for food can get one into trouble. Sure we have to eat to be Healthy. But when one enters in a state of craving and addiction to have the "food fix", one could easily allow himself to become lax and lenient over the strictness and the reliability of its supervision. We don't have to go further than the first day of creation where we find that craving for food caused the downfall of Man. The first craving for food was on the first day of creation when Chava was enticed to eat from the Aitz Hadaas by the Nachash. The passuk describes her craving to eat from it וכי תאוה הוא לעינים her eyes feasted on it and she experienced בולמוס a ravenous hunger to eat it (Bina Leitim chelek 2, derush 7). From then on one has to ensure that his eating will be a tikkun in the world, kosher permitted eating with the proper kavannah and intention as it states in Orach Chaim Siman 231.
Eating is a time of war with the yetzer harah. That is why bread is called לחם from the root word of מלחמה. The word crave is the vocal sound of the letters קרב which means battle. r. When it's time to eat we must realize that a battle is taking place especially if one feels that he craves the food he is eating. One must ensure that he is eating the food and not that the food is eating him. There is a story about a chassid who was sitting in his Succah and eating his soup with kneidlach as if there was no tomorrow. His Rebbe came to visit him and saw the way he was pounding those kneidlach. He remarked with surprise Do you realize that you are eating outside of the Succah. The chossid looked up to the sechachand saw that he was directly in the Succah and couldn't understand what the Rebbe meant. The Rebbe continued, You are not in the Siuccah but rather in your kenidlach and soup.
The Baal Shem Tov writes that eating kosher food with the right state of mind and conduct brings redemption to the neshamos that are in the food yearning to be redeemed. He explains the passuk Tehillim 107 רעבים גם צמאים נפשם בהם תתעטף that the reason why a person gets hungry and thirsty is to bring a redemption to the souls that are wrapped inside the food and water.
The mitzvah we recite twice a day is ואהבת את ה אלקיך בכל לבבך ובכל נפשך ובכל מאדך one must love Hashem with all his heart soul and money. In essence the Torah is really telling us to crave Hashem to the point that besides ruchniyus there is nothing else that is worthy of craving. One can desire other things and activities but not crave them. Using the same word crave to describe gashmiyus instead of reserving it for the most holy of activities, is deemed blasphemus to one who truly understands the purpose and meaning of life on earth.