Reducing the amount of salt that children eat could provide a short-cut to keeping them slim, British researchers reported on Wednesday.
They found that children who ate less salt drank fewer sugary soft drinks and could reduce their risk of high blood pressure and obesity.
Writing in the journal Hypertension, they said this could lower rates of heart attack and stroke in later life.
"Sugar-sweetened soft drinks are a significant source of calorie intake in children," said Dr. Feng He of St. George's University of London.
"It has been shown that sugar-sweetened soft drink consumption is related to obesity in young people," He added in a statement.
"If children aged 4 to 18 years cut their salt intake by half, there would be a decrease of approximately two sugar-sweetened soft drinks per week per child, so each child would decrease calorie intake by almost 250 kilocalories per week."
One pound of body weight equals 3,500 calories.
He and colleagues analyzed data from a 1997 national survey of more than 2,000 people between 4 and 18 in Britain. More than 1,600 boys and girls had salt and fluid intake recorded in a diary, with everything they ate and drank weighed.
"We found that children eating a lower-salt diet drank less fluid," He said. "From our research, we estimated that 1 gram of salt cut from their daily diet would reduce fluid intake by 100 grams per day."
The children who ate less salt also drank fewer sugar-sweetened soft drinks, and He predicted that a 1 gram reduction in salt would reduce sugar-sweetened soft drink consumption by 27 grams a day, after factoring in age, gender, body weight and level of physical activity.
He said parents should check labels, choose low-salt food products and not add salt during cooking and at the table.
"Small reductions in the salt content of 10 percent to 20 percent cannot be detected by the human salt taste receptors," she said.
According to the American Heart Association, healthy adults should reduce their sodium intake to less than 2,300 milligrams or 2.3 grams per day. This is about 1 teaspoon of salt.
Americans and Britons consume up to 75 percent of their sodium from processed foods like tomato sauce, soups, canned foods and prepared mixes.
(Reporting by Maggie Fox, Editing by Will Dunham)