People think lettuce is nutritionally worthless, but nothing could be farther from the truth. You can’t leave it out of your weight-loss plans, not at 10 calories per cup of raw romaine. It provides a lot of filling bulk for so few calories. And it’s full of vitamin C, too. Go beyond iceberg lettuce with Boston, bibb and cos varieties or try watercress, arugula, radicchio, dandelion greens, purslane and even parsley to liven up your salads.