LAUSR

In the twilight hours of Christmas Eve, many families in North America provide cookies and milk for Santa Claus. Avoiding excessive calorie intake is increasingly emphasized as part of a healthy life style [1]. An interesting question is how many calories Santa will have consumed that night on his trip to this region? This topic has been commented on extensively in the last few years (Table 1); however, the methodology used to determine households visited and calories consumed per household varies widely, is often incompletely disclosed, and when it is disclosed, often seems arbitrary. Furthermore, no source we reviewed attempted to address the specific metabolic demands of Santa Claus or the thermic effect of the food he consumes. Here we attempt to construct amore accurate picture of the Calories (herein use of a capital “C” refers to large/ food calories) both ingested and expended by Santa Claus on Christmas Eve 2017. We restrict our data to the United States of America, where survey information is available on pertinent attitudes and behaviors in the population. In 2013, a Pew survey showed that of United States adults with children, 49% planned to make preparations for Santa’s arrival on Christmas Eve, as did a surprising 22% of adults who were not parents or guardians [2]. According to the 2016 American Community Survey (United States Census Bureau), there are 118,860,065 households in the USA, with an average size of 2.65 persons. Of these, there were 36,846,620 households with children <18 years of age (31%; [3]). If 49% of United States households with children make preparations for Santa’s arrival, this yields 18.1million households. Furthermore, of the households without children, if 22% prepare for