I made this recipe just the other day and it came out very good.. Please remember we are on maintenance which means we eat some carbs..
This is the version for low carb that I used... Well, as low carb as possible..

MEATBALLS:
1 pound of minced meat ...... (I used minced chicken) to make the meatballs..
1 egg
2t garlic powder (I used granules)
3T ketchup
Now, it calls for some breadcrumbs to thicken up the minced which I used , otherwise you can't make balls that hold together without falling apart..
I also added some Worchester sauce for a bit of a tang.. We all have our meatball recipe, but I used this one..

Make small meatballs and put them directly in the slow cooker

SAUCE:
1/2 cup apple cider vinegar (white vinegar would do also)
1/4 cup ketchup
3T soy sauce
1/2 cup splenda brown sugar
1 small can of pineapple chunks (in its own juice) with the juice.. Add the juice to the sauce but add the pineapple on top of the meatballs
Wisk the sauce and pour over the meatballs and pineapple

Cook on high for 3 to 4 hours ...............
After about 2 hours, add some sweet red pepper cut into chunks to the pot and mix gently (any pepper would do)
Also take a taste of the sauce and adjust according to taste.. I found it quite good at that point but added a bit more water to make more sauce..
Now, the recipe calls for some cornstarch mixed with water to thicken up the sauce.. I passed on that as it isn't exactly low carb but there are other methods of thickening up the sauce if you would like it thicker to serve over something as a base.. I served it over some small egg noodles as a base and I sprinkled some sesame seeds before serving..
Yes, the sauce was loose so maybe something to thicken up the sauce a bit would be a good idea.. perhaps 1T of cornstarch would do it..

We found it one of the better dishes I have made in some time.. Very flavourful and pleasant.. The vinegar and brown splenda really made it sweet and sour.. The pineapple was pleasant.. The pepper wasn't overdone and mushy..