The Fourth Doctor

• WOTC Official Reminder Textofficial rules
  Food — , , Sacrifice this artifact: You gain 3 life.

• WWizards of the Coast2023-10-13
  Official Ruling
  If the top card of your library changes during the process of casting a spell or activating an ability, you can't look at the new top card until the process of casting the spell or activating the ability ends (all targets are chosen, all costs are paid, and so on).
• WWizards of the Coast2023-10-13
  Official Ruling
  Essentially, The Fourth Doctor lets you play with the top card of your library revealed only to you. Knowing what that card is becomes part of the information you have access to, just like you can look at the cards in your hand. You may look at the top card of your library whenever you want, even if you don't have priority. This action doesn't use the stack.
• WWizards of the Coast2023-10-13
  Official Ruling
  Unlike other creature types in Magic that are each only one word, the two words "Time Lord" represent a single creature subtype. Time Lord is the only two-word creature type.
• WWizards of the Coast2023-10-13
  Official Ruling
  Neither "Time" nor "Lord" are creature types. Some older cards were printed with the subtype "Lord," but all of those cards have updated Oracle card text that removed that type.
• WWizards of the Coast2023-10-13
  Official Ruling
  If an effect instructs you to choose a creature type, you may choose Time Lord.
• WWizards of the Coast2024-11-08
  Official Ruling
  You can't sacrifice a Food to pay multiple costs. For example, you can't sacrifice a Food token to activate its own ability and also to activate Maraleaf Rider's ability.
• WWizards of the Coast2024-11-08
  Official Ruling
  Whatever you do, don't eat the delicious cards.
• WWizards of the Coast2024-11-08
  Official Ruling
  Food is an artifact type. Even though it appears on some creatures, it's never a creature type.

Rulings via Scryfall