This is from my 85 year old Mother's recipe collection.

1	(6 oz) pkg.	Orange jello
1	pint	Orange sherbet
1	small can	Pineapple tidbits, drained
1	can	Mandarin oranges, drained

Dissolve jello in 1 cup boiling water plus 3/4 cup pineapple juice. Let set in refrigerator until slightly thickened. Blend in sherbet and drained fruit.

This could be considered a low-fat if you stick to one actual serving.