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AMPM - Validation Study
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Data Collection Period
Study Design
Doubly-Labeled Water Method
Study Status
 AMPM logo

Purpose- Use biomarkers of energy and protein intake to validate the AMPM   Collecting information via interview

Sample- 524 healthy volunteers from the Washington DC area:

Data Collection Period- July 2002 to September 2003

Study Design- Each volunteer entered the study for a 14-day period, and data were collected during 4 visits to the Beltsville Human Nutrition Research Center plus 3 telephone contacts. During the study period, participants were interviewed three times using the AMPM, and asked to report all foods and beverages eaten the previous day. These food recalls were conducted four to five days apart. The first interview was conducted in-person and subsequent recalls were conducted by telephone. Over the 15 months of the study, interviews were conducted on every day of the week and during all seasons of the year. Because the AMPM is the instrument used to collect dietary data in What We Eat in America, the dietary intake interview component of the National Health and Nutrition Examination Survey (NHANES), the environment in which participants were interviewed replicated that used for the NHANES dietary interview to the extent possible.


Doubly Labeled Water Method- The doubly labeled water method was used to validate energy intake. It provides an accurate measure of total daily energy expenditure. When individuals are weight stable (not gaining or losing weight), energy expenditure and energy intake are equal. Thus, the energy expenditure estimates that the method provides serve as an excellent biomarker for energy intake.

On their first visit to the study center, participants drank a dose of doubly labeled water and then collected urine samples daily over the 14-day study period. Doubly labeled water contains a higher concentration than usual of deuterium and oxygen-18, which are naturally-occurring stable isotopes of hydrogen and oxygen. The rates at which these isotopes are excreted in urine can be measured and used to calculate total daily energy expenditure.

Study Status: