Protein & Calorie Calculator for Caterers, 1980-1995. White disc shaped calculator made of card. Central rivet allows user to rotate sliding bar to calculate the calories and protein in different foods. Marked in black and red ink. 'Obtainable from Austick's University Bookshop Leeds'. 'Devised by the Catering Research Unit, University of Leeds in association with The Local Government Training Board and Department of Education and Science.'
Calorie counting, now a mainstay of dieting, became popular in the early 1900s. Prior to the calorie and protein contents of foods being easily accessible and the now-mandatory nutritional information declared on prepacked foods, people had to rely on estimated amounts or use calculators such as this. The central rivet allowed the user to rotate a sliding bar and calculate the calories and protein in different foods, ranging from fruit and vegetables to canned meats.