Hello Paul Wilson
The apostle Paul wrote; Know ye not that ye shall judge angels. I Cor 6:3

Angels are spiritual beings with a form.
1. Their heavenly form
2. The form they take as men when used by God as messengers.
3. The form the Watchers took in order to do the evil of Genesis 6, whereby Jude wrote Jude 6, the angels that kept not their First Estate and await the Judgement of the Great Day.

Their form is always one in which they are clearly [not] as we preceive as Ghosts. Even our form once we receive our glorified bodies is a form that a robe can be worn. To wear a robe their has to be a form to hang it on. In Revelation we read the Martyrs are given white robes and ask to wait a little season until the others are come. Even our spirit has a tangable form.
I would like to share this tiny bit of information if I may. I have from the age of 5 to 7yrs had visions.Even today I am taken to places and see people and events. One night my husband said he had trouble sleeping with his back pain, and he was turned toward me and saw me raise up from my body and sit on the side of the bed. My body was still laying on the bed, yet my form was sitting up and after a few minutes my form lay back down into my body. He recognized my form.
I can understand what Paul meant when he said whether in the body or out of the body I know not, God knows. But I was there.

The body our Lord had while with us was flesh and was subject to all the things of the flesh. Food was a needful part of that. We know also that after His resurrection in His glorified state, He ate with the deciples.
While the children of Israel during the Exodus; God rained down Manna from heaven for them to eat. This Manna was the very food of the angels.It contained ALL that the Isrealites needed to sustain themselves. It was because of their murmering that God sent the quail.
If we are to judge angels and be righteous judges ruling and reigning with Christ, then we must be needful of Nothing !
We cannot be swayed in any way or means by those to whom we are rightfull judges over. We cannot be threatened by harm because if we are shot at, or run through by a spear etc. we are eternal beings.
Moses gave us a picture of  how this will be, in Exodus chapter 18 beginning at verse 13. Some being rulers of thousands, and some over hundreds, and some over fifties, and tens. The greater issues will be brought unto the Lord, as was the case with Moses.
The question you pose about eating will really not be an issue for us in eternity. Remember we will be at the Marriage Super of the Lamb.

TIME:
Time is ordained of God for man. Man will live eternally upon the earth in this period of time called " the eternal perfect state". There will be no more seas. All the earth is 2/3's oceans at this present time, but in the eternal perfect state there will be only fresh water and much land for man to use.  In Gen 1:14 God set Time in place when He said; Let them be for Signs first, and for seasons, and for days, and for years.
In Gen 8:22 God said; [While the earth remaineth], seedtime and harvest, and cold and heat, and summer and winter, and day and night shall not cease.
Jesus tells us in Matt 24:22 that the days of terrible troubles/ tribulation will be shortened for the elects sake. In Verse 35,and 36 Jesus tells us that heaven and earth shall pass away, but of that day knoweth no man, no, not even the angels of heaven, but my father only.
So we know that heaven and earth will pass away. When? is up to the Father.
Thus we know Time will go on! Whether this means that heaven and earth pass away as we now know it, or completely pass away is not really clear. I say' that I believe that the heaven and earth passing away is when God makes a New heaven and New earth for the eternal perfect state.
I say this and believe this because it is called the ETERNAL perfect state. Eternal is forever.

Breathing;
In Genesis chapter 1 beginning in verse 26, God said let us make man in our own image, after our likeness and let them have dominion ie;.
We were created in the image and likeness of God. (Gen 1:27) and also in Genesis Chapter 2:7 God breathed  into his (mans) nostriles the breath of life; and man became a living soul.
God; Fahter son and Holy ghost, breathe. As an eternal being God breathes. We know that we shall be like Him( Jesus) at our translation, glorification. Therefore we shall also breathe in our eternal state.
If our creator whom we are fashioned breathes , and we are to be like Him, it only stands to reason that we also will have breath .

God Bless you
KML