This is my family's traditional holiday dessert. It isnt' low-carb, but it has no added sugar, so is more low-carb friendly than your usual desserts. You can use some grapefruit and/or tangerines in place of some of the oranges.
small can (8 oz.) pineapple, crushed or tidbits, in own juice
coconut, flaked (optional, preferably with no sugar added)
Over a bowl, so you catch the juice as you cut, peel oranges, then section so that the tougher membranes separating the sections are removed. (You end up with the inside pulp of the orange sections in the bowl. Squeeze the remaining part to extract the juice into the bowl, then discard the excess pulp.) You should end up with about 2 1/2 cups of orange sections and juice. If they do not taste sweet, you can add a teeny bit of fructose or sugar or artificial sweetener. (I didn't count this in the calculations.)
Add whole can of pineapple, including juice. Combine and chill.
Just before serving, put a couple slices of banana in each serving dish, then add about 1/3 c. of the oranges and pineapple, plus some juice. Sprinkle with a small amount of coconut, if desired.
9 g. carb = about 1/3 c. citrus plus a few slices of banana. 0 protein, negligible fat unless you use a lot of coconut.