Harrison et al., (1975) details food waste audits conducted in Tucson Arizona in 1973 and 1974. The group of researchers featured Dr. William Rathje of the Garbage Project (https://en.wikipedia.org/wiki/Tucson_Garbage_Project ), who was one of the first researchers to highlight our profligate ways by digging up landfills, using archeological principles.
Dr. William Rathje, left
Their research included sorting through waste samples collected from households but also inferring the amount of food purchased from food waste sorted. Avoidable food waste was sorted into a number of categories and also split into “straight waste” (i.e. had not been presented for consumption) and plate scrapings.
Waste samples were collected from two randomly selected households, per selected census tracts (bi-weekly in 1973 and weekly in 1974) and the wastes sorted into food waste categories. Using 1974 data they estimated that Tucson households disposed 173 pounds (78.6kg) of edible/avoidable food waste annually (they did not consider unavoidable food waste in their study).
The researchers estimated that the average household purchases between 0.9763 tons (887kg) (1974) and 1.069 tons (971kg) of food annually. Of this they estimated that households waste between 8.9% (1974) and 9.7% (1973) of total food, purchased for the household, and that the value of this food was between $80-$100 (1974 dollars) annually. The main contributors to the cost of food waste included meats, cheese, fresh vegetables and fruit.
• Households bought between 878 and 971 kg of food annually
• Between 8.9-9.7% was wasted
• Residents disposed 78.6kg/year of avoidable food
• It was worth between $80-$100 (1974 US dollars)
Harrison, G. G., Rathje, W. L., & Hughes, W. W. (1975). Food waste behavior in an urban population. Journal of nutrition education, 7(1), 13-16.