The study led by Kiyah J. Duffey, a doctoral candidate in the department of nutrition, and Barry M. Popkin, Ph.D., professor of nutrition and a fellow at the Carolina Population Center, disclosed that over the past 37 years, the number of calories adults get through beverages has nearly doubled.
The study used nationally representative data where 46,576 American adults aged 19 and older and their patterns of beverages were examined between 1965 and 2002.
Researchers found that, over these 37 years, total daily intake of calories from beverages increased by 94 percent, providing an average 21 percent of daily energy intake among U.S. adults.
"Water intake was measured from 1989 to 2002, and during that time, the amount of water consumed stayed roughly the same, but the average adult consumed an additional 21 ounces per day of other beverages," Popkin said.
"This has considerable implications for numerous health outcomes, including obesity and diabetes as this is just adding several hundred calories daily to our overall caloric intake," he added.
The biggest difference that the researchers observed was that the 2002 beverage patterns were more complex than they were in 1977.
There were just five beverages that dominated the patterns in 1977.
As noted in previous studies, 23 percent more adults reported drinking soda between 1965 and 2002 (accounting for an additional 108 calories per day) while calories from whole-fat milk declined nearly 45 percent (from 119 calories per day in 1965 to 69 calories per day in 2002), Alcohol (up 73 calories per day) and fruit juice (up 20 calories per day).
In 2002, there were eight beverages consumed in significant quantities - and new beverages appeared in these 2002 patterns.
Fruit and vegetable juices and diet beverages were not important in 1977 patterns, but were in 2002."
"One of the strengths of this study," Popkin said, "is that we examined the full range of beverages consumed, providing a broad understanding of the role of beverages, and patterns of beverages, to overall dietary intake."
The study is published in the November issue of Obesity Research.