A teacher friend of mine has been teaching low carb nutrition to his Life Science classes. He had them track their food on Fitday.com for three weeks. At the end of the three weeks, they each looked at all of their Fitday pie charts and percentages of nutrients and found that from day to day, each individual's pie chart/percentages were very stable. Next, each student drew his/her typical daily pie chart on one of three blackboards/two whiteboards. Each student stood under the drawing of his/her pie chart while another class came in to judge. The students bodies matched the pie charts: the greater the carbohydrate content of the daily diet, the more apparent the body fat on the student.