A food-waste total appears simple until researchers ask what was counted. Some studies include edible and inedible parts; others separate household, restaurant and retail waste. Measurement may rely on weighing, diaries, bin analysis or estimates, each with different strengths. Two percentages cannot be compared responsibly unless their boundaries align.
Clear metadata turns a headline number into usable evidence. Reports should state the sector, period, population, material definition and method, then disclose uncertainty. Consistent measurement helps reveal whether prevention policies work over time. It should not become a reason to postpone action where repeated evidence already shows a substantial problem. Comparability depends on definitions, methods and transparent uncertainty. Once boundaries are visible, policy makers can track change over time without pretending that unlike estimates are identical.