When combined with less physical activity than in decades past, the greater energy consumption significantly raises the risk of heart disease, stroke, hypertension, diabetes and other health threats, University of North Carolina at Chapel Hill researchers say.
The study, conducted at the UNC schools of public health and medicine, also found that all age groups ate more restaurant food -- including fast food -- than a generation ago.
A report on the research appears in the May issue of Obesity Research, a professional journal. Authors are nutrition doctoral student Samara Joy Nielsen, and Drs. Anna Maria Siega-Riz and Barry Popkin, assistant professor of maternal and child health and nutrition and professor of nutrition, respectively, in the UNC schools of public health and medicine.
“Dietary patterns are rapidly shifting in the United States, and these changes are important contributors to the growing epidemic of obesity and diabetes facing Americans,” Popkin said. “Clearly the problem is that Americans are eating too much food. The shifts in where we are eating, as well as the types of food, are critical.
“This new study makes an important contribution by showing how uniform the changes in the types of food eaten and the locations of food consumption are across all age groups, he said. “This is not a problem that only faces teens or young adults but one that faces all Americans.”
Nielsen said the research involved analyzing nationally representative data from the 1977-78 Nationwide Food Consumption Survey and three separate Continuing Surveys of Food Intake by Individuals. She and her mentors divided the overall sample of 63,380 people into four groups depending on their ages – 2- to 18 years old, 19-39, 40-59 and 60 and above.
“We looked at all kinds of foods including desserts, salty snacks, candy, french fries, hamburgers, pizza, low and medium fat milk products and meats and hot dogs,” she said. “Among our findings were that even though the two younger age groups were consuming more of these high-energy foods like french fries and burgers, they were still eating them in the same proportion to other age groups as they were 25 years ago. That means this obesity epidemic is definitely environmental not just specific to certain age groups”
UNC researchers also found large increases in snack eating and strong decreases in consumption of low- and medium-fat milk and medium- and high-fat beef and pork, Nielsen said. In 1977, for example, snacks produced 11.3 percent of the average American’s energy intake, while by 1996 that figure had climbed to 17.7 percent, which is more than a 50 percent increase.
“Although the elderly still snack the least, with 14 percent of their energy coming from snacks, they have had the largest jump in snacking, up from 7.7 percent in 1977, which is almost double,” she said. “Among people under age 39, pizza and salty snack consumption rose as much as 143 percent.”
To their knowledge, no previous studies looked at total energy consumption across the entire population, Nielsen said.
“By now, most people know they should eat more fruits and vegetables and less high-energy foods, but that doesn’t mean they are doing it,” she said.
“Americans of all ages could help protect their health now and in the future with food lower in energy density like vegetables. These foods are not only full of nutrients and micro-nutrients like vitamins and minerals, but also of water so that you get filled up while taking in fewer calories.”
The U.S. Department of Agriculture supported the surveys, which involved interviewing Americans about what and where they and their children had eaten over the previous few days and where the food they ate came, from such as stores and vending machines.
By DAVID WILLIAMSON
UNC News Services
Siega-Riz and Popkin are fellows at UNC’s Carolina Population Center.
Note: Nielsen can be reached at (919) 966-1499 or 966-9676. Popkin’s number is (919) 966-1732, and his email is popkin@unc.edu.
News Services Contact: David Williamson, (919) 962-8596
School of Public Health Contact: Lisa Katz, (919) 966-7467
Journal
Obesity Research