Think one little sugary soda won’t make a difference on your waistline? Think again.

If people replace just one calorie-laden drink with water, they can reduce body weight and improve overall health, according to a Virginia Tech researcher.

“Regardless of how many servings of sugar-sweetened beverages you consume, replacing even just one serving can be of benefit,” said Kiyah J. Duffey, an adjunct faculty member of human nutrition, foods, and exercise in the College of Agriculture and Life Sciences and independent nutrition consultant.

Consuming additional calories from sugary beverages like soda, energy drinks, and sweetened coffee can increase risk of weight gain and obesity, as well as Type 2 diabetes and cardiovascular disease.

Duffey’s findings, which were recently published in Nutrients, modeled the effect of replacing one 8-ounce sugar-sweetened beverage with an 8-ounce serving of water, based on the daily dietary intake of U.S. adults aged 19 and older, retrieved from the 2007-2012 National Health and Nutrition Examination Surveys.

Duffey, along with co-author Jennifer Poti, an assistant professor of nutrition at the University of North Carolina at Chapel Hill, showed that this one-for-one drink swap could reduce daily calories and the prevalence of obesity in populations that consume sugary beverages.

The 2015 Dietary Guidelines for Americans recommend that no more than 10 percent of daily calories come from added sugar and that calorie-free drinks, particularly water, should be favored.

“We found that among U.S. adults who consume one serving of sugar-sweetened beverages per day, replacing that drink with water lowered the percent of calories coming from drinks from 17 to 11 percent,” Duffey said. “Even those who consumed more sugary drinks per day could still benefit from water replacement, dropping the amount of calories coming from beverages to less than 25 percent of their daily caloric intake.”

As Duffey found, a reduction in the amount of daily calories coming from sugary drinks also improves individual scores on the Healthy Beverage Index – a scoring system designed to evaluate individual beverage patterns and their relation to diet and health based on standards set forth by the Beverage Guidance Panel and the Dietary Guidelines for Americans.

Duffey developed this index in 2015 with Virginia Tech nutrition researcher Brenda Davy, a professor of human nutrition, foods, and exercise in the College of Agriculture and Life Sciences and a Fralin Life Science Institute affiliate. Their preliminary data showed that higher scores correlate to better cholesterol levels, lowered risk of hypertension, and in men, lowered blood pressure.

The broader goal of the index is to help people identify what and how much they drink each day, as drinking habits can impact eating habits.

Higher calorie drinks, such as sweetened soda and high-fat milk, have been associated with diets rich in red and processed meats, refined grains, sweets, and starch, according to a 2015 review study by Duffey, Davy, and Valisa Hedrick, an assistant professor of human nutrition, foods, and exercise in the same college at Virginia Tech. Lower-calorie drinks, such as water and unsweetened coffee and tea, were associated with alternative diets rich in fruits, vegetables, whole grains, fish, and poultry.

Diet drinks are also healthier alternatives to sugary drinks, explained Duffey, but other research has shown that people who drink water over low-calorie alternatives still tend to eat more fruits and vegetables, have lowered blood sugar, and are better hydrated.

The initial study was funded by the Drinking Water Research Foundation, an independent not-for-profit organization that supports research in areas related to consumer- and drinking-water-industry interest.

Written by Cassandra Hockman.

