Fizzy and sugary drinks are helping to push up the figures of obese children, suggests a small study in the US, and also result in deficiencies in essential vitamins and minerals.
Children who drank more than 12 ounces of sweetened drinks gained significantly more weight than children who drank less than 6 ounces a day, found nutritionists at Cornell University during a two-month study. And they had lower intakes of phosphorous, calcium and vitamin A.
The researchers explained that children do not reduce how much food they eat at meals for the calories they consume in sweetened drinks. The more sweetened drinks they consumed, the greater their daily caloric intake and the greater the weight gain. They also tend to drink less milk, a crucial source of nutrients.
The survey supports previous findings that excessive sweetened drink consumption adversely affects nutrition and promotes obesity in school-age children, said David Levitsky, professor of nutritional sciences and of psychology at Cornell.
The researchers followed 30 children aged 6-12 for five days a week during a two-month period to monitor their daily sweetened drink and food consumption. Sweetened drinks included fizzy drinks, fruit punch, and bottled tea or drinks made from fruit-flavoured powders, such as grape and lemonade.
The more sweetened beverages the children consumed, the less milk they drink, said the Cornell team. Those who consumed more than 12 ounces of sweetened drinks ingested less calcium and zinc than the recommended amounts.
"These findings suggest that sweetened drinks may be a significant factor in the increase in obesity among children in the United States," said Levitsky. "And the fact that these drinks and fruit juice displace milk is dangerous, especially for girls, who need a strong supply of calcium before they mature or they will be at risk for osteoporosis after age 60."
Children who drank more than 16 ounces a day of sweetened drinks consumed four ounces less milk than children who avoided sweetened drinks and they obtained 20 per cent less phosphorus, 19 per cent less protein and magnesium, 16 per cent less calcium and 10 per cent less vitamin A per day.
Children consuming sweetened drinks took in 244 more calories a day than on days when they did not drink these beverages. Their solid food intake on these two occasions varied only by about 2 ounces, added the researchers.
Over the two months of the study, children who drank more than 16 ounces a day of sweetened beverages gained an average of 2.5 pounds, compared with a 0.7 to 1 pound gain in children who consumed on average 6 to 16 ounces of sweetened drinks a day.
The work, published in this month's issue of the Journal of Pediatrics, is part of the Ph.D. dissertation conducted by Gordana Mrdjenovic under Levitsky's direction.