Tuesday, April 20, 1999 Published at 15:21 GMT 16:21 UK
Milk 'helps control weight'
Milk was recommended for its weight control benefits
A regular glass of milk could help prevent young women piling on the pounds and reduce overall levels of body fat, a study has found.
Researchers at Purdue University in Indiana discovered that a high consumption of calcium slows weight gain for women in aged 18 to 31.
The researchers said women who consume calcium from dairy products, or who consume at least 1,000 milligrams per day, may reap the most benefits.
Their work was funded by the US National Dairy Council.
Keeps weight at bay
Dr Dorothy Teegarden, assistant professor of foods and nutrition at the university, presented her team's findings at a conference of the Federation of American Societies for Experimental Biology in Washington on Tuesday.
She said: "Our study is the first to show that, when overall calorie consumption is accounted for, calcium not only helps keep weight in check, but can be associated specifically with decreases in body fat."
The two-year study looked at 54 women.
Dr Teegarden said the women in the study were within normal weight ranges and followed no specific diet.
The participants kept a record of their diet, and the researchers used these records to assess consumption.
The researchers looked at the composition of the participants' bodies using a method called dual energy X-ray absorptiometry.
This provides measurements of muscle and fat mass of different areas of the body.
Calories and calcium
Women who consumed less than 1,900 calories per day with a daily calcium intake of at least 780 milligrams, either had no increase in body fat or lost body fat mass over the two-year period.
But women who consumed less than 1,900 calories per day but averaged less than 780 milligrams of calcium gained body fat mass over the same period.
The study showed that exercisers and non-exercisers benefited equally from high calcium intakes, but that women who consumed more than 1,900 calories per day did not benefit.
"There appears to be some sort of interaction with higher-calorie diets," Dr Teegarden said.
"When we looked at the data for the women with calorie intakes of more than 1,900, we found that the calories take over, and any potential benefits of weight-control from calcium are lost."
Women who got calcium from dairy products benefited from the weight control effect more than those who primarily used non-dairy sources or supplements.
However, they could not yet say whether women over 30 can benefit.
Looking forward to further research
Lyndell Costain, a spokesperson for the British Dietetic Association, said the findings were interesting but inconclusive.
She said the study group was too small to overcome difficulties in gathering accurate data.
"Assessing dietary records is notoriously difficult," she said.
"The data is often inaccurate - especially when it comes to judging quantities. Women are notoriously unreliable at this."
However, she said that she looked forward to seeing further work in this area.
"It's a good message to ensure that people are having enough calcium in their diet, if there is a possibility that it can help in weight control," she said.
"Having adequate calcium is important, particularly for young women whose bones are still developing."
Lack of calcium can cause osteoporosis, or brittle bone disease. Recent research suggested that teenagers with eating disorders were at greater risk of the disease.
Ms Costain said it was estimated that one in four teenage girls in the UK did not have enough calcium in their diet.
"If this finding encourages people to have enough calcium, then that's good," she said.