40 Years of Faulty Government Nutrition Research?
A new study has found that 40 years of nutrition research from the Centers for Disease Control and Prevention (CDC) might be completely invalid because the method used for collecting data was seriously flawed.
The study, led by Arnold School of Public Health at the University of South Carolina, found there were significant limitations in the measurement protocols that were used in the National Health and Nutrition Examination Survey (NHANES). Based on these limitations, speculations about how energy intake is linked to the prevalence of obesity are not "physiologically credible," said lead author Edward Archer.
Calories misrepresented among survey participants
The NHANES – conducted by the CDC and the U.S. Department of Agriculture – is considered the most comprehensive source of data on the health of children and adults in the United States. The survey includes interviews of self-reported food and beverage consumption and physical examinations to assess health and nutritional status of the population.
The problem with the last few decades of research, Archer said, is that the "calories in" and "calories out" reported by more than 50,000 participants between 1971 and 2010 don't add up – it would be impossible to survive on what most participants reported as their average energy intake, he explained. Obese individuals misrepresented their caloric intake the most, underreporting the number by an average of 716 to 856 calories per day.
Research is 'inherently flawed'
Since the nation's biggest tool for studying the relationships between nutrition and health isn't valid, Archer said, studies using this data are inherently flawed.
"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."
Public policy that is related to diet and health relationships is very limited, he continued.
"It is time to stop spending tens of millions of health research dollars collecting invalid data and find more accurate measures," he said.
More information from Archer's study can be found in the journal PLOS One.
Source: Arnold School of Public Health