How healthy a fruit salad is depends on what else is in it besides fruit. For example, the tomato and watermelon salad from My Recipes contains mainly healthy ingredients, while the Ambrosia salad from Food Network contains several unhealthy ingredients in addition to fruit.
Some of the additional healthy ingredients in the tomato and watermelon salad include red onion, red wine vinegar and extra virgin olive oil. The only unhealthy thing in the salad is the added sugar. The Ambrosia salad uses fresh pineapple, oranges, pecans and coconut, but it also includes unhealthy ingredients such as marshmallows, sour cream, heavy cream, sugar and maraschino cherries.