It sounds like a dieter's delight - a big bowl of healthy salad. However, if you don't know how to dress your green and leafy favorites, you could be in trouble. A salad can make the transformation from healthy to unhealthy quicker than you can say crouton. The foundation of the salad isn't at issue. Leafy greens, tomatoes, cucumbers, carrots, onions and other popular produce are loaded with vitamins and nutrients. When it comes to most fresh vegetables, you can consume unlimited amounts without worrying about your calorie count. Dark greens such as romaine lettuce or fresh spinach provide even more nutritional bang for your buck. Other great choices are red cabbage, peppers, beans, peas, mushrooms and beats. Lean proteins such as ham, chicken breast, hard-boiled eggs and grilled fish are filling additions to salads that should be enjoyed in moderation. If you're feeling extra daring, mix things up with fresh fruit - toss in a handful of strawberries, apples or grapes.