Do you want a trio with that?
Scientists, nutritionists, and health psychologists have taken a firm stance on what is considered a bad test for measuring energy intake. They have noticed that people are biased when they self-report their diet, whether the method is retrospective report or concurrent report. Moreover, they get the same amount of error if they are asking people what they consumed in the past month, or if people are recording their diet in a diary everyday for a month. People are underreporting the amount of calories they are eating, high calorie foods consumed, and they are overreporting low calorie foods consumed. For example, studies have found obese people consume fewer calories than non-obese people. This false reporting is most likely due to the stigma attached to obesity and high calorie foods. Many studies dedicated to energy intake influence national healthy policies, and it is concerning if these policies are not based on reliable and valid measures (Dhurandhar et al., 2014).
New Tests that Deviate away from Self-report Measures
There are researchers creating chin-mounted monitors that measure how many chews a person is taking. They hypothesized that the amount of chews will positively correlate with energy intake. Another test they proposed was a hand-to-mouth movement monitor that counts every time you put your hand to your mouth. The researchers suggest that the amount of hand motions will positively correlate with energy intake (Dhurandhar et al., 2014).
Will the new tests be a valid measure of energy intake?
Both the tests have a degree of error, because they are indirectly measuring energy intake. The chin monitor is measuring the amount of chews a person takes, but this does not measure energy intake, nor does it measure which foods they are eating. For example, a bag of baby carrots is 125 calories and three small cupcakes are 270 calories, but it takes a lot more chews to eat a bag of carrots than three small cupcakes. This is a situation where the amount of chews would be negatively correlated with energy intake. Another limitation to this test is if a person was chewing gum, the person’s increased chew rate would not correlate with higher energy intake. This test measures the amount a person chews, but it is not clear if this would correlate with higher energy intake.
The hand-to-mouth monitor has similar limitations to the chin monitor. This test measures how often a person puts their hand to their mouth, not the food that is being consumed. For example, if we use the above example, the three small cupcakes would have three movements to their mouth, whereas the person eating carrots would have many hand movements. Again, this test might not be able to measure increased energy intake based on increased hand motions.
Conclusion
The researchers are correct that their current test for diet based on self-report is not reliable. However, their test proposals are too indirect, and they will lead to misinterpretations. Further research will be required to create reliable and valid tests for energy intake.
Reference
Dhurandhar, N. V., Schoeller, D., Brown, A. W., Heymsfield, S. B., Thomas, D., Sorensen, T. I. A., Speakman, J. R., … the, E. B. M. W. G. (November 13, 2014). Energy balance measurement: when something is not better than nothing. International Journal of Obesity.
