There doesn't seem to be any place to bring food or drink. And what about WC?
And for single seat combat planes?
Fighter pilots do not have any problem taking food and drinks on flights. The biggest concern is to prevent foreign object damage (FOD) from items like crumbs, bottles, bags, etc. Otherwise, there are plenty of places to carry food to eat: your helmet bag, G-Suit pockets and flight suit pockets. I typically carry water with me in my g-suit pocket, and don't worry about food unless its going to be a long flight. Thankfully, training missions are rarely long enough that they require food in the cockpit, and it mostly just applies to deployments. Typical food usually includes protein bars, chocolate, cereal bars, etc. We try to avoid small loose foods like peanuts and M&M's because they could easily spill and FOD the cockpit.
Depending on cockpit altitude, the mask can be easily removed to either eat or drink. However, fighter cockpits are only partially pressurized, and, in the Super Hornet, there are times when cockpit altitude can be as high as 20,000ft. Sound judgement is required before removing your mask.
Edit: I've also seen guys incorporate camelpacks into their harness/vests as well.
Obviously life on board a fighter jet is cramped, and there isn't a lot of room to move your body, much less use the restroom. In addition to water, on every flight I carry an item called a pittle pack. As its been stated, its a plastic bag with powder in it that reacts to urine. The powder and urine mixture then turns to a jelly that helps prevent spillage, and the entire bag then rolls down and seals on itself.
Pittle packs present 2 major problems (three for carrier pilots):
First: Where the hell do I put this bag of urine? There isn't a lot of storage space on fighter aircraft and nobody wants to put a bag of urine in their g-suit pocket or helmet bag. Sometimes you can get away with placing the bags in the flight publication pockets, but you better be sure it doesn't fall out. The last thing you want is for the bag to fall, break, and then to smear about the cockpit as you continue with your mission.
Second: How do I get my junk out of this rocket powered chastity belt? My harness is strapped tightly 8 ways to the ejection seat, which is also cinched tightly to my g-suit. My g-suit has an opening for my crotch, but its tightly zipped into position over my flight suit. My flight suit has a zipper, but as stated, the zipper is covered by the g-suit. And just to add one last layer of difficultly to this impenetrable force field, I've got to dig myself out from between the folds of my boxer briefs. Success! I've managed to free myself only to discover that the tip of my business end is only barely protruding from this labyrinth of zippers and belts (size may not matter in the bedroom, but it sure as hell matters right now). The next question you have to ask yourself is, do I have enough time to keep digging, or do I need to attempt to arc it into the bag? Choose wisely.
Third (The carrier pilot): Boom, OK three-wire trap! Ah , the Naval Aviator. I drop bombs, piss in bags, and then return home to land on a boat. I'm pretty much a boss... and I'm covered in piss because I didn't secure my pittle pack before trapping on the boat. The bag, upon catching the three-wire, like a boss, rocketed across the cockpit and smashed against the bulkhead, exploding all over my legs. Always remember to secure your pittle packs before trapping on the boat, because even if your buddies didn't see it happen, you can guarantee the ground crew will tell them all about it.
Our female counterparts are forced to wear depends, I don't envy them at all. Brave souls.
Oh, and if its not pee, RIP.
In WWII long-range propeller fighters were usually fitted with an extraction tube, basically a pipe to pee into. This typically froze up in the cold, so you'd have to be pretty desperate. This is why Chuck Yeager said it was vitally important to pee before going on a mission.
Single seat fighters these days don't have any kind of facilities for that, pilots on long-range missions carry either a bag with absorbing gel in it or a plastic container with the same material in them. The USAF's nickname for these are "piddle packs". As for eating it's generally field rations, protein bars, candy bars, anything that is compact as space is an issue.
The U2 has a kind of toaster for heating ration packs.
Funny story told to an ex-RAF friend of mine when he was based in Cyprus:
Guy on a U2 mission over the USSR puts his lunch on and carries on with the mission. Suddenly he heard an enormous bang and his canopy was covered un red stuff.
He panics thinking he's been hit, starts looking everywhere for damage to both him and the aircraft (one would presume he put the lack of pain down to adrenaline).
After a while he realises there is no damage and he is not hurt. Turns out he had forgotten about the tomato-based thing he put in the heater and it had violently exploded.
FWIW, it is not just fighter pilots that have this issue. Many small private planes have facilitates to relieve one self.
My Cessna 340 had a relief tube with consisted of a narrow funnel with a trigger valve. You put the liquid (I will leave it to your imagination how you got it there) into the funnel and pulled the trigger. This opened the valve connected to a plastic tube that exited the aircraft under the tail. Since the cabin was pressurized there was a pretty descent pressure differential that resulted in a quick evacuation of the funnel.
For aircraft without such systems there are wee-packs that a pilot can buy. These contain a funnel area (they have different shapes and sizes for men and women) attached to a bag. The bag contains a powder that turns into a jelly trapping the liquid. When the flight is complete you dispose of the pack. See this product for an example.
SR71 crew would heat their meals by pressing them against the windows, as they were hot enough to burn fingers if the glass was touched. The crew would then eat with the helmet open. The SR71 was pressurized not for crew comfort, but rather to cool the electronics!
Fighter pilots, like the Mercury and Gemini missions, wear adult diapers in flight. As the joke goes:
What does the inside of an EVA suit smell like?
I believe that it was Alan Shepard who famously ruined some on-board electronics when his pee shorted them out.
Piddle packs are used. I've never used one so I can't say how tough they are to use. For food and drink just bring whatever you want. I usually keep a water bottle in my helmet bag but I know guys bring the AFE issued canteens and stick them in the lower pockets of their G-suit.
I did hear a story once of an old IP at my squadron that reached the EOR and had to piss. So he unstrapped and pissed over the canopy rail. I'm sure it happens more than I know though.
Also you can remove the mask to eat and drink. However in today's fighters you're breathing under pressure with a system called Combat Edge. In addition you can't be heard well if the mask is hanging. Or if you're hot mic, it annoys the other cockpit.