In developing countries, the fraction of food waste in the composition of…

Municipal solid waste (MSW) composition is closely tied to a country's income level: the organic/biodegradable food-waste share is highest in low- and middle-income economies and declines as income rises, while paper, plastic, glass, and other packaging/recyclable waste rises with income. This happens because wealthier economies consume more processed, packaged goods (inflating the non-organic waste share), whereas lower-income economies rely more on fresh, minimally packaged food, which generates a larger food/organic-waste fraction relative to the total waste stream.

Applying this principle to developing countries specifically: authoritative solid-waste assessments (such as the World Bank's What a Waste 2.0 overview and UNEP/ISWA's Global Waste Management Outlook) consistently report that food and organic/green waste makes up roughly half or more of total municipal solid waste in low- and middle-income countries, with figures in the low-to-mid 50s percent range being typical. That places the developing-country food-waste share well past the 40% mark, so the typical range quoted for developing countries is 'greater than 40%.'

• 10-15% describes a far smaller slice of the waste stream - closer to what a single non-organic category (such as plastics) contributes in many waste-composition studies, not the food/organic share in developing-country municipal solid waste.

• 20-30% is closer to the food-waste share more often reported for high-income, heavily packaged waste streams, where paper and plastic waste dilute the organic fraction - not the picture typical of developing countries.

• 25-35% still falls short of the roughly 50%-or-more organic/food-waste share documented for low- and middle-income countries; it understates how dominant fresh-food waste is in these economies' waste streams.

Because the documented developing-country figure clears 40% by a wide margin, and none of the three lower brackets match that data, the range 'greater than 40%' is the one consistent with the evidence.