Choose foods that are high in volume and low in calories. We're talking tons of veggies! Ilana Muhlstein, MS, RDN, co-creator of Beachbody's 2B Mindset nutrition program, told POPSUGAR that vegetables are the food group you want to be filling up on the most. "They are high in volume and weight and fill up our stomachs, which helps us register the feeling of fullness," Ilana said. Veggies aren't just for lunch or dinner! Eat veggies with every meal and snack.