Diarmid Logan
March 4th, 2004, 05:55 PM
http://www.eurekalert.org/pub_releases/2004-03/aha-dmf022404.php
Dairy, moderate fat, carbohydrate intakes reduce obesity in young
teens
American Heart Association meeting report
SAN FRANCISCO, March 4 – Children who ate few dairy products and had
low or high intakes of dietary fat gained more weight than those on a
moderate fat diet, according to a study presented today at the
American Heart Association's 44th annual Conference on Cardiovascular
Disease Epidemiology and Prevention.
"The rise in obesity in the nation's young people may be partly due to
fewer home-cooked meals, more calorie-dense foods, and more takeout
and prepackaged dinners," said Lynn L. Moore, D.Sc., associate
professor of medicine at Boston University School of Medicine. "There
has also been a shift toward higher intake of sodas, rather than milk.
"Some of the dietary trends of the past couple of decades may have
contributed to reduced intake of beneficial foods, such as dairy
products. Adolescent girls, in particular, have reduced their
consumption of dairy products, in part due to fear of gaining weight.
If weight gain is a concern, reduced-fat dairy products may be
substituted for full-fat products."
As part of the Framingham Children's Study (FCS), Moore and her
colleagues analyzed dietary habits of 106 families with one child 3 to
5 years old at the start of the study. They collected three-day food
diaries for the children one to four times each year. The diaries
included detailed descriptions of the food, portions, brands and
recipes consumed over a 12-year period from preschool to adolescence.
Researchers determined which dietary factors might be associated with
excessive gains in body fat during that period. They studied
macronutrients such as fat, protein and carbohydrates and
micronutrients, such as calcium and other minerals. They also studied
intake of foods in each of the major food groups in the USDA's food
guide pyramid. The researchers assessed body fat by measurements of
children's height and weight as well as skinfolds from five sites on
the body.
Children with higher-fat diets (35 percent of calories or more) and
lower-fat diets (below 30 percent of calories) gained more weight
throughout childhood than those who had moderate intakes of fat (30 to
35 percent of calories).
By early adolescence, children with generally high-fat diets had an
average skinfold measurement of 104.6 millimeters (mm) and those with
low-fat diets had 92.2 mm. In contrast, children with moderate fat
intakes had 74.7 mm of body fat.
"While it is not surprising that children with a high-fat diet had
excessive gains in body fat, we were surprised that children on
low-fat diets also had excessive gains in body fat," Moore said.
The researchers found that children with the lowest intakes of dairy
products gained much more body fat over an eight-year period. One
third of children in the study had low dairy intake (less that 1 ¼
servings per day for girls and less than 1 ¾ servings per day for
boys). These children had gained about three millimeters more skinfold
fat each year than children with moderate to high intakes of dairy
products. Increased consumption of fruits and vegetables was also
associated with lower gains in body fat.
"Animal studies suggest that calcium may play a role in fat
metabolism," Moore said. "A diet low in calcium may increase the
levels of certain circulating hormones that in turn promote the
storage of energy in fat cells. Restricted calcium intake may lead not
only to increases in weight and blood pressure, but also to a
reduction in bone density in the growing child."
Increased obesity is "part of the price we're paying" for the
convenience of high-fat fast-food meals, prepackaged dinners and
takeout foods, Moore said.
The American Heart Association says the best diet includes a moderate
consumption of dietary fat with high intakes of fruits, vegetables and
dairy products.
Other researchers in the study were Martha R. Singer, M.P.H., R.D., M.
Loring Bradlee, M.S., and R. Curtis Ellison, M.D.
Dairy, moderate fat, carbohydrate intakes reduce obesity in young
teens
American Heart Association meeting report
SAN FRANCISCO, March 4 – Children who ate few dairy products and had
low or high intakes of dietary fat gained more weight than those on a
moderate fat diet, according to a study presented today at the
American Heart Association's 44th annual Conference on Cardiovascular
Disease Epidemiology and Prevention.
"The rise in obesity in the nation's young people may be partly due to
fewer home-cooked meals, more calorie-dense foods, and more takeout
and prepackaged dinners," said Lynn L. Moore, D.Sc., associate
professor of medicine at Boston University School of Medicine. "There
has also been a shift toward higher intake of sodas, rather than milk.
"Some of the dietary trends of the past couple of decades may have
contributed to reduced intake of beneficial foods, such as dairy
products. Adolescent girls, in particular, have reduced their
consumption of dairy products, in part due to fear of gaining weight.
If weight gain is a concern, reduced-fat dairy products may be
substituted for full-fat products."
As part of the Framingham Children's Study (FCS), Moore and her
colleagues analyzed dietary habits of 106 families with one child 3 to
5 years old at the start of the study. They collected three-day food
diaries for the children one to four times each year. The diaries
included detailed descriptions of the food, portions, brands and
recipes consumed over a 12-year period from preschool to adolescence.
Researchers determined which dietary factors might be associated with
excessive gains in body fat during that period. They studied
macronutrients such as fat, protein and carbohydrates and
micronutrients, such as calcium and other minerals. They also studied
intake of foods in each of the major food groups in the USDA's food
guide pyramid. The researchers assessed body fat by measurements of
children's height and weight as well as skinfolds from five sites on
the body.
Children with higher-fat diets (35 percent of calories or more) and
lower-fat diets (below 30 percent of calories) gained more weight
throughout childhood than those who had moderate intakes of fat (30 to
35 percent of calories).
By early adolescence, children with generally high-fat diets had an
average skinfold measurement of 104.6 millimeters (mm) and those with
low-fat diets had 92.2 mm. In contrast, children with moderate fat
intakes had 74.7 mm of body fat.
"While it is not surprising that children with a high-fat diet had
excessive gains in body fat, we were surprised that children on
low-fat diets also had excessive gains in body fat," Moore said.
The researchers found that children with the lowest intakes of dairy
products gained much more body fat over an eight-year period. One
third of children in the study had low dairy intake (less that 1 ¼
servings per day for girls and less than 1 ¾ servings per day for
boys). These children had gained about three millimeters more skinfold
fat each year than children with moderate to high intakes of dairy
products. Increased consumption of fruits and vegetables was also
associated with lower gains in body fat.
"Animal studies suggest that calcium may play a role in fat
metabolism," Moore said. "A diet low in calcium may increase the
levels of certain circulating hormones that in turn promote the
storage of energy in fat cells. Restricted calcium intake may lead not
only to increases in weight and blood pressure, but also to a
reduction in bone density in the growing child."
Increased obesity is "part of the price we're paying" for the
convenience of high-fat fast-food meals, prepackaged dinners and
takeout foods, Moore said.
The American Heart Association says the best diet includes a moderate
consumption of dietary fat with high intakes of fruits, vegetables and
dairy products.
Other researchers in the study were Martha R. Singer, M.P.H., R.D., M.
Loring Bradlee, M.S., and R. Curtis Ellison, M.D.