Soup consumption may help manage weight, according to Iowa State nutrition professor

AMES, Iowa – With the chill of autumn setting in and more Americans turning to a piping hot bowl of soup to fight off the cold, a new study led by an Iowa State University researcher raises the possibility that eating soup more frequently may reduce the likelihood of overeating.

James Hollis, an assistant professor of food science and human nutrition, is the lead author of a paper published recently in the journal Plos One that says Americans who eat soup are less likely to be overweight. Hollis said the results are likely due to the ability of soup to keep eaters feeling full for longer periods than other foods.

“Soup is a satiating food,” Hollis said. “Accordingly, these findings suggest that increased soup consumption can help manage body weight.”

The study drew from data collected between 2003 and 2006 by the National Health and Nutrition Examination Survey, conducted by the National Center for Health Statistics.  Holis and Yong Zhu, a post-doctoral researcher and epidemiologist at the University of Iowa and a co-author of the study, analyzed a sample of 4,158 adults in the United States between the ages of 19 and 64.

After controlling for other possible factors, the analysis indicated that soup consumption was associated with a lower body-mass index, waist circumference and a reduced risk of being overweight than respondents who said they had not eaten soup in the previous 12 months. The study also looked for a connection between soup consumption and the prevalence of metabolic syndrome, a combination of medical conditions that increase the risk of heart problems, but the data didn’t support any such relationship, Hollis said.

The analysis, when compared with similar studies around the world, showed that Americans eat soup less often than populations in other countries. In Japan, for instance, around half the population consumes soup on a daily basis.

“In our study we also found the frequency of soup consumption in the United States was much lower than reported data from other countries such as Japan, where the prevalence of obesity was much lower,” Zhu said. “Increased consumption of soup, especially low-sodium soup products, is recommended.”

The study didn’t distinguish between different kinds of soups, Hollis said, because doing so would have created sample sizes that would be too small to be meaningful. Instead, the study used a general definition of soup as a dish with high liquid content derived from some kind of broth.

The study doesn’t establish a causal relationship between soup consumption and obesity, but future studies may be able to, Hollis said. Even so, he said people who are looking for healthy ways to manage their weight should consider making soup a more common part of their diet.

“A cause-and-effect relationship can’t be shown in a study like this, but the results do suggest that soup could have a role to play in managing weight,” Hollis said.