The Progressive Increase of Food Waste in America and Its Environmental Impact

TLDR

Food waste drives excess freshwater and fossil fuel use and releases methane and CO₂ from decomposition, contributing to global climate change. The study calculates the energy content of nationwide food waste by comparing the US food supply to the amount consumed by the population. Consumption was estimated with a validated metabolic model linking body weight to food intake. Per‑capita food waste has risen ~50% since 1974 to over 1400 kcal/day, now comprising more than one quarter of freshwater use and about 300 million barrels of oil annually.

Abstract

Food waste contributes to excess consumption of freshwater and fossil fuels which, along with methane and CO2 emissions from decomposing food, impacts global climate change. Here, we calculate the energy content of nationwide food waste from the difference between the US food supply and the food consumed by the population. The latter was estimated using a validated mathematical model of metabolism relating body weight to the amount of food eaten. We found that US per capita food waste has progressively increased by ∼50% since 1974 reaching more than 1400 kcal per person per day or 150 trillion kcal per year. Food waste now accounts for more than one quarter of the total freshwater consumption and ∼300 million barrels of oil per year.