Posted on 12/11/2013 at 07:30:43 PM by Student BloggerBy Larry Istrail, ACCN Blogger
Dr. Dale Schoeller of the University of Wisconsin spoke at ACCN about one of the hottest areas in nutrition and diet: methods of improving dietary assessment measures. Schoeller is a biomedical physiologist that studies energy metabolism and human obesity, body composition, and stable isotope techniques for macronutrient metabolism.
One of the most popular current methods for measuring dietary intake is the 3-day food record, which is a paper diary that study subjects fill out and send to the researchers. However, there are many problems with this method. It introduces a non-random sample of measured days, since study subjects choose which days to track. Additionally, Dr. Schoeller noted that 20% of subjects underestimate in a short-term diary and that percentage rose to 60% as the number of days reported increases. This is due to various inaccuracies introduced by the subject, such as social desirability bias and serving size measurement error.
Below are three emerging technologies profiled by Dr. Schoeller which offer promise for improved obesity research and accurate dietary measurement:
Remote Food Photography Method (RFPM)
In this method, study subjects would take a picture of their meal that would be submitted electronically to researchers for analysis. In the laboratory, trained registered dietitians use these photographs to estimate the portion size of food selection and plate waste by comparing these photographs to the standard portion photographs. In one paper, the RFPM method was accurate to within a few percentage points of actual energy content. Of course this method will not help with burritos, sandwich content, coke vs. diet coke, apple juice vs. beer. Nevertheless, this is dramatically better than the current technology we use today.
Hapifork is an industrially designed electronic fork that monitors the speed at which you place food into your mouth. If you place two consecutive bites in your mouth with less than a 10 second pause, the fork vibrates, training you to develop a Pavlovian response to eating too fast. The theory being that if you eat slower you may eat less. As they describe it on their website, “eating too fast leads to poor digestion and poor weight control.” While this is a nice idea in theory, there is no strong data to my knowledge that eating slower will result in long-term weight control or improved digestion. It is also very impractical to take anywhere outside the house.
Another idea some researchers have thought about is monitoring the muscles of mastication in your head, to determine when and how long you eat. In a paper published on this topic, investigators created a sensor “used to capture movement of the lower jaw from 20 volunteers during periods of quiet sitting, talking and food consumption.” They were able to develop an accuracy of about 80%.
These methods offer varying degrees of promise in improving the quality of our dietary research. But they all create an important innovative impetus for our energy assessment measurements to improve from the unfortunate gold standard of today: paper and pen.