Which is worse Sugar or salt can hold your fats in your body?

Sugar and salt don't make you fat. However consumption of a lot of sugar and carbohydrates contributes to the problem. Sugar/Carbohydrates is your body's major source of energy and essentially its fuel. The more carbs you eat, the more readily available energy the body has to burn and metabolize. Fat is really not used in any productive way by the body and it tends to be stored as reserves. When you cut back on your carbs, the body reverts to its fat storages as a secondary source of energy. In other words, if you moderate your carb and sugar intake, the body will tend to burn more fat. If you consume excessive amounts of carbs and sugar, the body will not need to breakdown and metabolize the stored fats. The body will break down carbs, fat and muscle in that order.

Salt will make you retain fluids (swell up). Sugar will turn to fat.