It is generally true that sugar get converted to fat. It is best to have a diet that is more natural, with the lease amount of preservatives, high fructose corn syrup, trans fats/partially hydrogenated oils, etc. I have 2 very basic rules for a healthy diet...
1. What would Jesus eat? Meaning that if the food wasn't around 2,000 years ago than chances are it is not good for you.
2. If your food doesn't die then it will kill you... meaning that the higher the shelf life the worse it is for you (more preservatives). A good example is an apple versus a twinkie.
Good luck!
Antonio Marotta, D.C.