Watching your weight? Stock up on lemons and limes. For a whole variety of reasons, these tangy little citrus fruits can be a dieter's best friend.These bright and beautiful fruits are staples in kitchens everywhere. Affordable, easy to use, simple to store, and readily available year-round, limes and lemons deliver a powerful store of nutrition. They're excellent sources of vitamin C, which is essential to almost every aspect of good health; it has anti-inflammatory properties, is crucial to the efficient function of the immune system, and is an important and effective antioxidant. Vitamin C has also been proven effective in the treatment and prevention of rheumatoid arthritis and osteoarthritis. In addition, both lemons and limes contain compounds called limonoids, which are believed to be effective in fighting certain types of cancers.But it's really the flavor of limes and lemons that make them invaluable to dieters. A little lemon or lime juice adds a zesty sparkle that brings out other flavors in foods without adding fat, sodium, or extra calories. For example, topping a baked potato with a squeeze of lemon or lime juice instead of the usual butter, salt, and and sour cream can drastically reduce the fat, calories, and sodium. Reaching for a glass of natural lemonade instead of a carbonated soft drink will reduce your calorie intake and at the same time promote healthy digestion, and the same goes for using lemon in your tea instead of cream and sugar.In addition, the tart and tangy flavor of lime or lemon juice can be a surprisingly effective salt substitute. Try it on meats, rice, casseroles, potatoes, vegetables - just about any food that you would generally sprinkle with salt will be just as delicious with a sprinkling of lime or lemon juice instead. And when it comes to salad dressings, either lime or lemon juice, or even both together, can work wonders. Replacing the vinegar in a vinaigrette with the juice of a lime or lemon creates a light, refreshing dressing that works perfectly with just about any salad, from leafy greens to a fresh fruit mix. Here are two excellent low fat, low calorie, low sodium dressings that will spark up your salads.Creamy Lemon Lime Vinaigrette- 2 tablespoons lemon juice- 2 tablespoons lime juice- non-caloric sweetener to taste (about 1/2 to 1 packet, depending on how sweet you like your dressing)- shake of salt substitute- Black pepper to taste- 1 garlic clove, crushed and minced- 2 tablespoons extra virgin olive oil- 1/4 cup Greek yogurt- about a tablespoon of grated ParmesanCombine everything in a small bowl and whisk briskly to combine. Store, covered, in refrigerator and whisk or shake vigorously before serving.Herbed Lemon Dressing- 2 to 3 tablespoons lemon juice- sugar substitute to taste (about 1/2 to 1 packet)- salt substitute and black pepper to taste- 1 garlic clove, crushed and minced- 1/3 cup extra virgin olive oil- 1 tablespoon of finely minced fresh oregano, basil, or parsley (or a combination of the three).Put all ingredients into small bowl and whisk well to combine. Store, tightly covered, in fridge.