Well I don't know that my ideas will work for everyone....   but I have child-proofed for two generations of kids in my home so I may have some experience that could be of some help.  I will admit that some of these suggestions may seem a bit hars or to the extreme, but I must ask how important it is to us to keep our food intact instead of rampaged by ADHD fingers.

First of all, we have a small kitchen.  It's 16x7.5 feet.  We have made this room off limits to the grand-kids.  There's only enought room out there to cook or wash dishes and such and if that's off limits to the kids, then I already have a start on protecting our food from an eternally starving stomach.

Secondly, in case they decide to conveniently forget that they are not allowed in the kitchen, I lock everything possible.

First if you have a pantry we'll start here.  We've nearly always had a pantry.  I built one in our home for my wife upon which we keep a slide bolt to protect our incredible edibles from our grand-son, of whom we have custody.  Pantries in homes I've had before when my kids were growing up were pad-locked.  We will soon padlock this one too.

If a pantry is unavailabe, maybe shelves put up in a room or space in the basement, the laundry or spare hall closet could be easily adapted for doubling as a pantry.  These are not usually visited by kids, but if you chose to use the laundry or hall closet or basement for food,  you must then secure all doors to this area or it will be a favorite haunt for the kids.  It might be good and it will help to get a steel door on these rooms IF you can afford it  ~(8^D)   but of course, I understand that if I'm this concerned about my food and the cost, I can't afford a steel door.  :^/

In the locked pantry we keep all sharp knives, sweets, boxed and bagged foods like crackers, cereals pretzels and chips.  Anything that can be dangerous or opened by little thieving hands and eaten.

HINT:  I never tell them that things like the Ice Pops we just bought are theirs or they'll want them all immediately.  Instead, I tell them that they are mine and I'll give them to them when they have been good or when I'm good and ready.  Maybe this is why my grand-son been prayering every morning that God help me to be good and do "good things".   :^)

In this pantry we also keep the freezer and fridge.  Frozen or not, if ADD/ADHD kids can get into it they will eat it.  My grand-son has thawed things in his room and ate it later.  Grrrrrrr !

The cabinets in the kitchen have such things as pot holders, pots 'n' pans, canned goods and other things that cannot be opened and/or eaten.  If they eat these we won't have to worry about iron in their blood....   we have iron skillets.   :^)  LOL

Just in case, put the can opener in the pantry.  My Grand-son has opened canned foods in his room and really made a mess.  Recently he'd had the expensive baked beans all through his toy box so it's good to keep this can opener locked up.  If you have the electric variety you can have an outlet in your pantry where you can open these cans.

If you can't put the fridge and freezer in the pantry, here's how to prevent the kids from getting into them.

    1.  Get a medium weight link chain (steel) long enough to go around the fridge and/or freezer.
    2.  Go to a fish tank supplier and get some plastic hose that the chain will fit through.
    3.  Get a good sturdy pad lock at your hardware store.

Slide the chain into the hose.  The hose will protect the finish on the fridge and/or freezer.  Wrap the hose with chain around the fridge.  It might be good to put a hook of some kind on the end of the chain so you can hook it on the door handle so it won't get lost between the fridge and cabinets.  Then take your chain through the door handles and put the padlock through the end loops.

Oh....   I would also keep the man's bolt cutter and hack saw in a LOCKED area or they WILL find them and cut the chain.  Believe me these kids are very innovative and learn fast.

If you don't have a pantry, invest in a locking system for the cupboards.  Each of these are feasable in my opinion.  I've lived through this.

    1.  One could be indivual locks for each door.
    2.  Chose which set of cupboards you want to make a prohibited area.

Have a metal shop make brackets that you can fasten to the cabinet (1/8th inch stainless steel or aluminum should be fine.  The bracket should have a hole in it, say 1/2 inch in diameter (below).

Have them also make a rod about 3/16 inch less than the diameter of the holes in the brackets.  Have a plate on the end of the rod so the end can't go through the holes of the brackets.  Of course, the length of the rod should be just long enough that you can put it through to lock the doors in question and still be able to lock a padlock..  In the other end there will be a hole where a pad lock will fit (see below)

Put the brackets on the cabinets between the doors.  These brackets should be made as hidden hinges are.  Kids are good at using tools...   screwdrivers included.  If you have standard hinges it would be advisable to get new hidden ones.  If not, you will one day find all cabinet doors off the hinges and while the doors will still be attached to the rod, they will not be on the cabinets and your food will be raided.