If I wasn't doing keto, I'd love to put pineapple on meats. Haven't tried it on meatloaf, but it's excellent in the classic soy and garlic chicken.

Soy and garlic chicken, for those interested:

Just toss a quarter cup of soy and a tablespoon of minced garlic in a gallon bag with a couple pounds of boneless chicken (thighs are best), *optionally adding a bit of pineapple*, and let marinade for at least an hour or overnight. Grilled is best 👌 I bet pan fried or baked is great, too.