For people aged 31-50, eating a high proportion of "fast food" is associated with a higher body mass index (BMI). Image courtesy of Microsoft Clipart.

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Food Choices and Health Indicators

By Rosalie Marion Bliss
February 3, 2009

Many adults live life in the fast lane, and when the need for speed extends to mealtimes, they often reach for fast foods. A study by Agricultural Research Service (ARS) nutritionist Rhonda Sebastian shows that among U.S. men and women aged 31 to 50, obtaining a greater proportion of total calories from conventional fast-food restaurants was associated with a higher BMI, or body mass index. BMI is a ratio of weight to height that is used to gauge body fat in adults.

Sebastian is with the ARS Beltsville Human Nutrition Research Center in Beltsville, Md. ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture.

Sebastian and colleagues analyzed the eating habits of more than 2,000 volunteers aged 19 to 50. The analysis was based on responses collected from two 24-hour food intake questionnaires during the national food intake survey, "What We Eat In America," a component of the National Health and Nutrition Examination Survey, better known as NHANES.

In NHANES and this study, fast foods were defined as all foods that survey respondents said they obtained from fast-food and pizza establishments, without waiters/waitresses, including carryout, delivery and drive-through service. Total calorie intake and the percentage of calories derived from fast-food sources were calculated for survey respondents, who were selected to be representative of the U.S. population.

The significant relationship between BMI and fast-food intake found among the 31- to 50-year age group was not found among the 894 volunteers who were in the 19- to 30-year age group.

The researchers also found that the survey respondents who obtained a larger percentage of their calories from fast foods consumed higher levels of discretionary calories overall. For an in-depth definition of discretionary calories, go to MyPyramid.gov at: http://www.mypyramid.gov/pyramid/discretionary_calories.html

The percentage of U.S. adults who met current MyPyramid food group recommendations was low, regardless of whether or not they reported consuming fast foods. The researchers concluded that strategies to help people meet recommendations must take into account the types of foods and beverages obtained from all sources, not just from fast-food establishments.