Boil 2 kinds of beans: white and red. Add the diced tomato. Supplement the salad with corn kernels and finely chopped greens of dill and parsley. Season lettuce 1/3 of the vinegar (as an option: you can add finely chopped onions previously marinated in vinegar) or lemon juice, pepper.
Tip: in the salad recipes for weight loss, it is better not to use canned beans, corn or peas, and cook a dish of fresh ingredients - boil beans, corn replaced baked or frozen, peas also take a fresh or frozen.