In line with the point of the article, I can attest to the difficulty of tracking food intake.  It&#x27;s an experiment I&#x27;ve done several times in the past 20 years.  The idea is not only recording everything eaten, but <i>weighing</i> every item consumed to assure accuracy.  Doing that for a week is a lot of work, but also highly educational.<p>What&#x27;s interesting, on repetition the experiment has shown 2 somewhat contradictory results.  Day to day there was wild variation in diet, always found surprises in what or how much I ate.  OTOH at the end of the week, the average daily calorie intake was very consistent&#x2F;predictable at 2100 +&#x2F;-100 kcal&#x2F;day.  Of course there was a wealth of info about my diet composition as well.<p>I&#x27;d understand how very difficult it would be to scale up my experiment to the point of having enough participants to make it scientifically useful.  In fact I&#x27;m not at all sure I&#x27;d recommend it to anyone unless the individual was so committed to the project to willingly put up with its arduous and tedious process.<p>However, as a personal nutrition learning tool nothing else I know of could possibly ever beat it.