Related Experiment Video
Updated: Oct 8, 2026

Palatable Western-style Cafeteria Diet as a Reliable Method for Modeling Diet-induced Obesity in Rodents
Published on: November 1, 2019
Where's the fat? Trends in U.S. diets 1965-1996
B M Popkin1, A M Siega-Riz, P S Haines
1Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27516-3997, USA. popkin@unc.edu
Background:
Controlling fat intake has been an ongoing health concern since the late 1950s. This study examines 30-year trends in food sources of fat intake. It focuses on both total fat and specific fatty acid classes to ascertain if there are trend differences by age, sex, or race/ethnicity.
Methods:
Nationally representative cross-sectional U.S. Department of Agriculture surveys from 1965, 1977-1978, 1989-1991, and 1994-1996 form the basis of this analysis, which compares 45,357 adults aged 18 years and older. Food files linked over time are used to create comparable food groups and nutrient values.
Results:
The proportion of fat in the diet from grain-based mixed dishes, higher-fat snack foods, and higher fat potatoes has increased to partially offset reductions in fat from dairy, red meat, and added fat categories. Food sources of fat differ by race/ethnicity and age. The percentage of fat from fast foods and ethnic foods increased over time from 1 to 11% of total fat. The ratio of visible to invisible fat declined considerably.
Conclusion:
While animal product-based sources of fat continue to require emphasis, the shift toward fast foods, fried foods, and grain-based mixed dish and edible oil sources requires more focus.
Related Concept Videos
Obesity
Fats as Energy Storage Molecules
Fats as Energy Storage Molecules
Regulation of Food Intake
Lipids: Dietary Sources and Requirements
Overview of Fatty Acid Metabolism
Fatty acids are catabolized in a process called beta-oxidation, which takes place in the matrix of the mitochondria and converts their fatty acid chains into two-carbon units of acetyl groups. The acetyl...

