Add a broth-based vegetable soup to your lunch or dinner. The liquid fills your stomach, leaving less room for higher-calorie foods. One study showed that people who started with soup ate 20% fewer calories during a meal. Stirring in beans, such as chickpeas or black beans, can give it more staying power because they’re high in protein and fiber. In fact, eating 3 cups of beans a week has been shown to boost weight loss.