A single serving of this hearty veggie adds up to a mere 46 calories. A serving also packs more than your daily-recommended doses of vitamins A and K, which can strengthen your immune system for a healthy metabolism, says Jonny Bowden, PhD, a nutritionist and the author of The 150 Healthiest Comfort Foods on Earth. Plus, a cup of collard greens contain 7.6 grams of belly-filling fiber. Research from the US Department of Agriculture shows that eating fiber-rich foods can lower your body’s absorption of calories from carbs.
Chicken noodle soup
“People who eat a broth- or vegetable-based soup before their meal consume fewer calories overall,” says Rania Batayneh, MPH, nutritionist and author of The One One One Diet. “The water in the soup helps fill you up and boosts satiety, and just the act of eating soup helps slow your eating down so that your body has time to notice feelings of fullness.” One Penn State study found that people who ate soup before digging into their entrees reduced their total calorie intake by 20%. Plus, chicken noodle varieties pack the protein, vitamins, and fiber you need to rev your metabolism even after your meal.