40 years of federal nutrition research fatally flawed

Four decades of nutrition research funded by the Centers for Disease Control and Prevention (CDC) may be invalid because the method used to collect the data was seriously flawed, according to a new study by the Arnold School of Public Health at the University of South Carolina. The study, led by Arnold School exercise scientist and epidemiologist Edward Archer, has demonstrated significant limitations in the measurement protocols used in the National Health and Nutrition Examination Survey (NHANES). The findings, published in PLOS ONE (The Public Library of Science), reveal that a majority of the nutrition data collected by the NHANES are not "physiologically credible," Archer said. These results suggest that without valid population-level data, speculations regarding the role of energy intake in the rise in the prevalence of obesity are without empirical support, he said. The NHANES is the most comprehensive compilation of data on the health of children and adults in the United States. The survey combines interviews of self-reported food and beverage consumption over 24 hours and physical examinations to assess the health and nutritional status of the US population. Conducted by the CDC and the U.S. Department of Agriculture, the NHANES is the primary source of data used by researchers studying the impact of nutrition and diet on health. "Throughout its history, the NHANES survey has failed to provide accurate estimates of the habitual caloric consumption of the U.S. population," Archer said. "Although improvements were made to the NHANES measurement protocol after 1980, there was little improvement to the validity of U.S. nutritional surveillance." These limitations "suggest that the ability to estimate population trends in caloric intake and generate public policy relevant to diet-health relationships is extremely limited," said Archer, who conducted the study with colleagues at the Arnold School. "The nation's major surveillance tool for studying the relationships between nutrition and health is not valid. It is time to stop spending tens of millions of health research dollars collecting invalid data and find more accurate measures," he said. Source