I think we need to be less hung up on the details, lest we turn fasting into a form of legalism, and not a tool of strengthening our spirituality.
Exactly, there are some very scrupulous priests who do not even want those parishioners with serious allergies looking beyond the five major ingredients in processed foods. What are they doing telling their parishioners to eat PROCESSED foods for Lent in the first place?
Most processed foods contain GMO corn and soy. As one Antiochian Priest said, if it's GMO, it is not lenten as you do not know what animal genes have been added by mad scientists to produce those GMO foods.
Boycott processed food. Eat organic non-GMO food the way God created it.
While I certainly agree with you on reasons of health, it can also be difficult for some to always afford such food, and others to have time to prepare a filling meal. Many working families don't always have time to fix a nice breakfast or lunch. Processed foods aren't the best for you, but it's sometimes hard to avoid.
That said, not all processed foods are things like big pastries or fatty snacks, and so I don't think they can all be considered inappropriate for Lent. They're aren't the ideal, but sometimes the ideal is beyond reach.
Monks dig up potatoes and carrots and add some greens like broccoli to make a daily Lenten soup.
Things grown in the garden can be delicious. Mushrooms can be grown in cellars. They are also very nutritious and if added to a potato, onion, and carrot soup, this can be a very hardy and nutritious soup.
A couple of sliced olives will give that soup a sensational flavor. No need to add olive oil.
Monks have that luxury. Those of us working in powerplants 10 - 13 hours per day, six or seven days a week do not. We either eat what we carry or eat what they serve us (we have a cafeteria there). Funny thing is, two priests have told me to do the best that I can, but make sure that I am alert and concentrating on my job, even if it means that I do not fast. The third insists upon keeping the fast and says that hunger is good for you and makes you dwell on the spiritual. Does anyone want to guess which two priests actually worked as something other than a priest during sometime of their life?
In any case, Lent used to be my favorite time of the Church year. I have come to hate it with a passion since becoming Orthodox. How wonderful it would be to see a thread discussing increased alms during lent and which charities could use the money most. Or, how best to go about visiting people in the hospitals or nursing homes. Or how we can best use the money that we are supposed to save with these "fasts" to best help those in our community that need the help. But no, we are too busy trying to out Jew the Jews in our meaningless works that benefit nobody but ourselves (if even that, since all the discussion and "look at me, I'm fasting" posts probably eliminate anything the fasting would have done). After all, let us remember the story of Jesus at the Last Judgment:
When I was hungry, you fed me.
When I was thirsty, you gave me drink.
When I was naked, you clothed me.
When I was sick, you comforted me.
When I was in prison, you visited me.
But I saw you eat a hamburger during the fast, SO YOU CAN GO TO HELL!
said Jesus never.