Okay, I know I'm posting a really implausible question, please be understanding....
Many years ago, a powerful mage went mad (occupational hazard; one does encounter eldritch horrors and reality-altering magic when one is a powerful mage responsible for keeping the world safe), harnessed the powers of the eldritch horrors he slain, and corrupted the world's mana, permanently altering our food. Each and every single food you can think of-Black Forest cake, sour gummi worms, hardboiled eggs, carrots-has gained adorable eyes, simple mouths, and primitive limbs (for examples of creatures with these traits, look at Kirby or Shopkins, the inspiration for this question).
Furthermore, each of these food items has gained both unique personalities and 'cultural' traits, along with the ability to speak (which comes with rudimentary-think caveman-intelligence). Food heals or reproduces by expending energy, which comes from the corrupted mana of the planet itself. For example, two hamburgers, side by side, release a bolt of energy that collides between them and poof! A baby-size hamburger appears. The two "parents" then have halved energy and must wait a certain amount of time before they can have another "child."
Furthermore, food items can merge. For example, flour, eggs, sugar, butter, and milk fuse into a cake (and without baking soda, since I just can't count that as actual food...). This cake will have the combined intelligence and traits of the ingredients that came together to make it, making it a superfood (the food equivalent of superhuman). Each food has instinctive awareness of merging and reproduction from the get-go, but they can't do either until they mature. This takes the same amount of time as recharging for a "parent."
Additionally, food does not need to eat and heals damage (or loss of mass, like when a cake is cut into slices) over time. One example would be that candy tends to dissolve in water; so if living candy is exposed to water, and isn't completely dissolved, it can gradually restore mass. Since energy is going into regeneration, the candy will be weaker and slower during this time. This principle makes any cold food (like ice cream) weak but generally unmelting when exposed to heat (say, room temperature, or a hot car, NOT a blowtorch).
Finally, food can grow (or heal) by absorbing other members of their kind or their ingredients; carrots can grow by absorbing carrots, while cakes have the alternate option of absorbing flour, eggs, butter, sugar, or milk to grow. Growing causes a proportional increase in intelligence.
As for when animal/plant matter becomes food for the purposes of this question: as soon as fruit is fully formed, it becomes food and comes off. Once vegetables (like a carrot or head of lettuce) are fully formed, they become food. Animal carcasses and so forth are not meat until they are prepared; for birds, this means being plucked, beheaded, and cooked, for snails and insects, this means being cooked, and for fish, they have to be either cooked, made into sushi, or cooked and canned (as for sardines).
For those interested (like Nzall), bulk food LIFE is simple. Take a scoop from a bag of flour, and that scoop is alive as well, but less powerful and intelligent than the entire bag. The bag then has a slight dip in power and intelligence.
My question is simple but complex: How Will This Impact Mankind's Interaction With Food?
As always I appreciate your input, and your feedback. If this question is too opinion-based, or needs additional information, I would greatly appreciate advice on fixing it.
EDIT: Thanks everyone, your answers were all very helpful and I'll be using pieces of each and every one.
EDIT 2: Clarification
Yes, the food feels pain-emotional pain, a sense of loss, whenever they lose part of themself. Exposing food to it's weakness-like heat for ice cream or water for bread-causes it physical and emotional anguish.
Where is the energy over time coming from? Eldritch monstrosities, things like Chthulhu, have an Aura of Discord. They generate chaotic (AKA magical) energy that the living food draws off of.