Binding water into food makes your stomach stay fuller for longer, Barbara Rolls, a professor of nutritional sciences at Penn State told CNN. And if you feel full, you're less likely to overeat.
Soup is also usually eaten slowly when compared to drinking a juice or smoothie, so you're more likely to feel satisfied. In addition, since soup has a high water content, you can have a nice-sized serving without taking in too many calories.
One study confirmed the weight-loss power of soup when comparing people who ate soup for a snack versus those who had chips and pretzels. The calories for soup and other snacks, as well as the daily total calories, were the same, but the soup group lost 50 percent more weight.
Souping is also easy on the digestive system, and depending on the type of soup you eat, it can be packed with vitamins and minerals, Dr. Mehmet Oz said.
Robin Foroutan, a registered dietitian and spokeswoman for the Academy of Nutrition and Dietetics, recommended that soups contain plenty of veggies, herbs, spices and healthy proteins such as lentils, beans, tofu or chicken and fish and bone broth.
What should you look out for?
The following are some concerns to look out for if you're souping:
Calories may be too low.
Some soup diets may be too low in calories, which can lead to muscle breakdown, registered dietitian Despina Hyde told The New York Times. For this reason, she said souping should be limited to one full day at a time.
Some soups aren't good choices.
Cream-based soups can be heavy on the saturated fat and calories, Healthy Women warned.
Short-term doesn't work well.
If you're souping for short periods of time, you probably won't reap huge results, Healthy Women added. But adding healthy soups to your diet can have a positive effect in the long term.