DIETARY STUDIES OF A WALKING TRIP. 147 
eat, the preparation of food was a comparatively simple matter. 
Bacon was fried for two meals, and several mornings beef tea 
was made from the prepared extract, and chocolate from milk 
chocolate to which was sometimes added several malted milk 
tablets. The entire amount thus prepared was divided between 
the two subjects and consumed at once. The amounts of all 
other food materials consumed at a given meal were regulated 
entirely by the appetites of the subjects. 
From these explanations, it will be apparent that it was in 
no sense the purpose of the investigation to follow any partic- 
ular theories as to either kind or amount of food eaten. In 
fact, aside from the weighing of the food, every effort was made 
to live exactly as if no dietary study were in progress. 
DETAILS OF THE DIETARY STUDIES. 
The method employed in conducting these dietary studies 
consisted in brief in determining the amounts of each food ma- 
terial eaten by each subject during each meal of the trip. 
From these data, the percentage composition and fuel value 
of the food materials, and the coefficients of availability, were 
computed the amounts of total and available nutrients and 
energy consumed by each subject throughout the experiment. 
The price paid for each article of food was likewise recorded, 
and served as a basis for observations as to their relative 
economy. 
Weighing of foods.—The amounts eaten of all solid food ma- 
terials were for the most part determined by weighing each 
man’s portion on a small hand balance. This balance was con- 
sidered sensitive to 10 milligrams with a load of 100 grams, but no 
weight greater than 70 grams was ever put upon it, and weights 
were taken only to grams as the general conditions of experl- 
menting were not sufficiently exact to warrant greater accu- 
racy. In the case of fancy cookies and similar articles made in 
molds of the same size and presumably of uniform weight, the 
above method was simplified by weighing a considerable num- 
ber of each, assuming that the average weight thus obtained 
was representative of the entire package, and thereafter record- 
ing merely the number eaten. The same plan was also fol- 
lowed for the raspberries and blueberries as a means of obviating 
many tedious weighings. 
