Table 1.

Categories of factors that influence household food waste or food waste related behaviours (organised to individual, household or external to the household levels). Factors are ordered from those most commonly identified in studies to those less commonly identified.

Individual (micro) level factors associated with food waste	Household (meso) level factors associated with food waste	External to household (macro) level factors associated with food waste
⋅ Demographics. Include an individual's age, gender, and educational and income levels. Food waste is positively associated with income level, and negatively associated with educational level and age. Associations with gender are contradictory across studies and less well evidenced for other demographic factors. ⋅ Attitudes. Include an individual's attitudes towards food and its value, food waste, food safety and risk, healthy eating and eating ‘fresh’ food. Food waste is negatively associated with attitudes about the value of food and food waste, and is positively associated with concerns about food safety and desires to eat healthily and ‘fresh’. ⋅ Time constraints. An individual's personal schedule and their available time for food related activities. The relationship of these factors to food waste is usually described generally. It's recognized that the unpredictability of life, and competing demands on an individual's time, can lead to food being wasted. ⋅ Perceived norms. An individual's personal and subjective norms about food and food waste. Perceived norms about the value of food and the need to reduce food waste are generally associated with lower levels of food waste. ⋅ Skills and knowledge. Include an individual's skills, knowledge and confidence in food storage, preservation, cooking, date-labels and meal planning. Greater levels of skills, confidence and knowledge are generally associated with lower levels of food waste. ⋅ Personal values and identity. An individual's moral stand-point towards waste, their broader ideologies and their particular self-identity. The relationship of these factors to food waste is usually described generally, with no direction of association shown. ⋅ Awareness. An individual's awareness and knowledge of food waste as an issue, together with its environmental and social consequences. Greater levels of awareness are generally associated with less food waste. ⋅ Perceived control. An individual's sense of control over their food waste and food related practices and behaviours. Lower perceived control is usually associated with higher amounts of food waste. ⋅ Intention. An individual's intentions to reduce food waste or to change food wasting behaviours. Higher intentions to reduce food waste are usually associated with lower food waste amounts. ⋅ Habits and emotions. The influence of individual's habits and emotions on food related behaviours. While generally understudied, evidence suggests that food related behaviours of an individual have a significant habitual and emotional component.	⋅ Demographics. Include the average size, income level and make-up of a household. Food waste is positively associated with household size and income, and if children are part of the household. Associations with other demographics are less well evidenced. ⋅ Needs and tastes of others. Includes the food-related preferences, desires and needs of others in a household. The relationship of household needs and tastes to food waste is usually described generally. Food waste emerges from the combined food related needs and tastes of all household members. ⋅ Equipment and infrastructure. Includes the physical food storage and cooking equipment within a household, as well as the presence of vegetable gardens. The presence of refrigerators and vegetable gardens, are associated with lower levels of food waste. Well-organised fridges and pantries are also associated with lower levels of food waste. ⋅ Combined time constraints. The combined schedules and available time of household members for food related activities. The relationship of time related factors to food waste is usually described generally. Food waste emerges from the unpredictability of life, and competing demands on time, associated with a group of people living together. ⋅ Norms. Include the food related routines and rituals of the household. The relationship of household norms to food waste is usually described generally. Routines to do with households eating together are negatively associated with food waste. ⋅ Dynamics between householders. Include the interactions, communications and decision making between household members about food and food waste. The relationship of household dynamics to food waste is usually described generally. Adult authority over children's eating and combined decision making about food purchasing is associated with less food waste. ⋅ Roles. The food-related roles and identities of different members of a household (assigned by others, or taken up on their behalf). The relationship of different roles and identities to food waste is usually described generally, with food waste emerging from the actions or decisions of individuals in relation to their role in the household. There is often a gender component to these roles, with women playing a key part.	⋅ Demographics. Includes a country's (or region's) GDP, level of urbanization, food retail density and level of food security. Food waste is positively associated with GDP and levels of urbanization, and negatively associated with food security and the number of supermarkets and grocery stores (as opposed to restaurants and take-away meal venues). ⋅Retail. Includes food retailers' marketing, advertising and sales strategies, package sizes, food pricing and promotion of particular cosmetic and freshness standards. The relationship of retail factors to food waste is often described generally. Some evidence that package sizes and food promotions are associated with greater food waste. ⋅ Physical settings (other than retail). The influence of food waste education activities at school. Generally understudied, there is evidence to suggest that what children learn at school can influence food related knowledge and awareness at home. ⋅ Legal and regulatory frameworks. Include a country's (or region's) food health standards, date-label requirements and cost of waste disposal. The relationship of these frameworks to food waste is usually described generally, with recognition that externally imposed food safety requirements indirectly influence when food is disposed. Domestic food waste collection charges are negatively associated with food waste. ⋅ Social. Food related social obligations, identities and standards. The relationship of social factors to food waste is often described generally, with recognition that social identities and obligations determine who we eat leftovers with and influence our desires to be a good host through over-catering. ⋅ Culture/place. Include culturally and geographically defined notions of edibility, norms about food sharing, and ideals of abundance. The relationship of cultural and place-based factors to food waste is usually described generally and tends to have an indirect influence.