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Cited by 103Food Waste Reduction and SustainabilityAgriculture Sustainability and Environmental ImpactWaste Management and Recycling

Valuing the multiple impacts of household food waste

Open access
von Massow, Michael, Parizeau, Kate, Gallant, Monica, Wickson, Mark, Haines, Jess, Ma, David W. L., Wallace, Angela, Carroll, Nicholas +1 more·2019·Frontiers in Nutrition
DOI 10.3389/fnut.2019.00143PMC PMC6738328
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Abstract

The Commission for Environmental Cooperation (CEC) has estimated that Canadian households waste 85 kg of food per person annually. Food waste has become an increasingly common focus for policy, regulation, interventions, and awareness-raising efforts in Canada. However, there is still a relative dearth of data to inform such decision-making processes or to provide narratives to contextualize behavior change efforts. In this paper, we describe the results of an uncommonly detailed observational study of household food waste. A total of 94 families with young children living in Guelph, Ontario chose to participate in this study. Over the course of multiple weeks, we collected data on their food purchases, food consumption, and waste generation. All three streams of waste (garbage, recycling, and organic waste) were audited and the food type, degree of avoidability, and weight of each individual component of the organic waste stream was recorded. Using this highly granular data set, we found that the average household in our study generated approximately 2.98 kg of avoidable food waste per week. This estimate was then contextualized in terms of economic losses (dollar value), nutritional losses (calories, vitamins and minerals) and environmental impacts (global warming potential, land, and water usage). In short, weekly avoidable food waste per household was calculated to be equivalent to $18.01, 3,366 calories and 23.3 kg of CO2. These multiple valuation frameworks, which are based in detailed observations of family food behaviors rather than estimations derived from system-wide data, will enable more informed and urgent conversations about policy, programming, and interventions in order to reduce the volume of wasted food at the consumer level.

AI snapshot

Written from the paper’s full text.

TL;DR

This study audited household food waste in 94 Guelph, Ontario families with young children and valued avoidable waste economically, nutritionally, and environmentally. It found average avoidable food waste of 2.98 kg per household per week, equivalent to $18.01, 3,366 kcal, and 23.3 kg CO2 weekly.

Key findings

  • Average total food waste was 4.41 kg per household per week (229.32 kg/year); avoidable food waste averaged 2.98 kg/week, with fruits and vegetables making up 65.5% and bread/cereals 24.2% of avoidable weight. The top 25 items represented almost 60% of total avoidable weight, led by bread (9.0%), tomato (5.9%), and apple (3.8%).
  • Economic loss from avoidable waste averaged $18.01 per household per week ($936.52/year); median weekly cost was $16.60, first quartile $6.47, fourth quartile $31.35. Cost increased by approximately $5.70 per kilogram of avoidable food waste, with a Spearman correlation of 0.92 between weight and value.
  • Nutritional loss averaged 3,366 kcal per household per week (175,032 kcal/year), equivalent to the recommended daily caloric intake for 1.7 adults or 2.2 children. Wasted fruits and vegetables contributed 62% of wasted fiber, 85% of vitamin A, and 96% of vitamin C.
  • Environmental impact averaged 23.3 kg CO2 per household per week (median 16.9 kg; 1.2 tons/year), 6.7 m2 land per week (348.0 m2/year), and 5.0 m3 water per week (260.0 m3/year; 260,000 liters/year).

Methods

  • Cross-sectional Family Food Skills Study in Guelph, Ontario, with 94 households (54 in 2017, 40 in 2018) that had at least one child aged 2–8 and parents with no prior nutrition or food training; recruitment was at daycares, community health centers, social media, and word of mouth, with a $100 grocery gift card incentive.
  • Waste audits were conducted over four consecutive weeks in 2017 and three consecutive weeks in 2018 during summer; all three streams (garbage, recycling, source-separated organics) were collected and each food item was identified, weighed, and categorized into six food groups and avoidable/unavoidable/possibly avoidable categories, yielding 316 avoidable food items.
  • Economic values used receipts and online grocery prices for ~12% missing data; nutritional values used the Canadian Nutrient File; environmental values used LCA meta-analysis for global warming potential, FAOSTAT and Nijdam et al. for land, and Water Footprint Network databases for water.

Limitations

  • The authors state high variability within and between households, voluntary participation and possible self-selection bias, time-intensive study requirements that may deter less organized families, participant awareness of waste audits, Guelph’s active waste-education context, a small sample of 94 households not representative of socio-demographic diversity, and limited generalizability beyond families with young children.
  • The authors also state they could not observe food waste disposed of by other means (e.g., sink garburators, fed to animals) and may have missed some liquid dairy items; the 2018 audit was shorter due to logistical constraints and a holiday long weekend.
  • Evident from the methods: unknown/unidentifiable foods were proportionally distributed into known categories, generic food labels sometimes required selecting a midpoint nutritional entry, and environmental estimates rely on external LCA, yield, and water-footprint databases with region- and boundary-related uncertainties.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3389/fnut.2019.00143

Cites

Statistics

Nothing to recompute.

Claims the paper makes

0 of 49 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    The average household in the study generated approximately 2.98 kg of avoidable food waste per week.

    “we found that the average household in our study generated approximately 2.98 kg of avoidable food waste per week.”
    Quote in the paperSubstantial claim
  • Findingown data

    Weekly avoidable food waste per household was equivalent to 23.3 kg of CO2.

    “weekly avoidable food waste per household was calculated to be equivalent to $18.01, 3,366 calories, and 23.3 kg of CO2.”
    Quote in the paperSubstantial claim
  • Findingown data

    There was considerable variability between households in waste generation rates.

    “There was considerable variability between the waste generation rates of households.”
    Quote in the paperNot a substantial claim
  • Findingown data

    A small number of high waste households increased the sample average weekly avoidable food waste.

    “There were a small number of high waste households that increased the sample averages.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Fruits and vegetables made up approximately two thirds (65.5%) of the avoidable food waste weight.

    “Fruits and vegetables made up approximately two thirds of the avoidable weight.”
    Quote in the paperNot a substantial claim
  • The quote only partly states this claim. 1
  • Classified as probably not a substantial claim. 43
  • May combine two claims. 42

  • The quote only partly states this claim.

    Findingown data

    Breads and cereals made up 24.2% of the avoidable food waste weight.

    “Breads and cereals also made up a large portion (24%) of the avoidable weight.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given

    Food waste discourse in Canada is not coherent but has common themes in messaging from key influencers.

    “While food waste discourse in Canada is not coherent, there are some common themes that emerge in the messaging from key influencers.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Findingreasoning

    Food waste discourse is still emergent in Canada, and there is room to shape the story-lines framing the public conversation about this issue.

    “In contrast, food waste discourse is still emergent in Canada, and there is room to shape the story-lines that are framing the public conversation about this issue.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given

    Health issues in Canadian food waste discourse are usually framed around the benefits of eating commonly wasted food rather than focusing on the nutrients lost when food is wasted.

    “However, health issues are usually framed around the benefits of eating commonly wasted food, rather than focusing on the nutrients that are lost when food is wasted.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The audit identified 316 avoidable food items in the waste streams.

    “Once each food item was categorized, we generated a list of 316 avoidable food items found in the waste streams.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Avoidable waste from fruits and vegetables represented the largest share of land use but a lower proportion of land use relative to total avoidable food waste weight.

    “Once again, avoidable waste from fruits and vegetables represented the largest share of land use but was a lower proportion of land use relative to the proportion of total avoidable food waste weight.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The average composition of the avoidable food waste stream did not change much as total waste volume increased; the increase was consistent across all food categories rather than driven by a specific category.

    “While there was considerable variation from house to house and significant differences in total waste generation, the average composition of the organic waste stream did not change much as volume grew. Some households clearly disposed of more edible food, but the increase was consistent across all the food categories rather than being driven by a specific category.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Fruits and vegetables represented 66% of the total weight of avoidable food waste and almost 40% of the CO2 generated by total avoidable food waste.

    “Fruits and vegetables represented 66% of the total weight of the avoidable food waste and almost 40% of the CO2 generated by the total avoidable food waste.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The first quartile of households had an average cost of $6.47 per week while the fourth quartile had an average cost of $31.35 per week.

    “The first quartile of households had an average cost of $6.47 per week while the fourth quartile had an average cost of $31.35 per week.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The global warming potential associated with avoidable household food waste was 23.3 kg CO2 per household per week, with a median of 16.9 kg.

    “The global warming potential (GWP) associated with avoidable household food waste calculated in this study was 23.3 kg CO2 per household per week, and the median value was 16.9 kg (Table 5).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Eighty-four percent of the variation in value was explained by total weight of wasted food, and total cost increased by approximately $5.70 per kilogram of avoidable food waste.

    “Eighty-four percent of the variation in value was explained by total weight of wasted food, and total cost increased by approximately $5.70 per kilogram of avoidable food waste.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Meat and fish represented 6% of total avoidable food waste weight but 13% of total cost.

    “Meat and fish represented a small proportion of the total weight (6%) but a much larger proportion of total cost (13%).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    Bread and cereal wastes represent lost calories, fiber, and vitamins, and minerals.

    “Bread and cereal wastes also represent lost calories, fiber, and vitamins, and minerals.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Avoidable household food waste was equivalent to 6.7 m2 of land per household per week, with a median of 5.6 m2.

    “Avoidable household food waste was estimated to be equivalent to 6.7 m2 of land per household per week. The median value was 5.6 m2.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Water usage associated with avoidable household food waste was 5.0 m3 per household per week, with a median of 4.6 m3, or 260.0 m3 annually.

    “Water usage associated with avoidable household food waste was calculated to be 5.0 m3 per household per week (the median value is 4.6 m3), or the equivalent of 260.0 m3 annually.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Fruits and vegetables make up most of the avoidable food waste generated by all households, followed by bread and cereals, and then meat and fish.

    “Fruits and vegetables make up most of the avoidable food waste generated by all households, followed by bread and cereals, and then meat and fish.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingcitation

    The National Zero Waste Council's estimate of more than $1,100 in edible food waste per household per year equates to $21.12 per week.

    “This equates to $21.12 per week.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The National Zero Waste Council estimated that an average household wastes more than $1,100 in edible food per year.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    Calories in weekly avoidable food waste appear to be relatively normally distributed with a slightly long tail to the right.

    “Calories appear to be relatively normally distributed with a slightly long tail to the right (Figure 5).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    Fruits and vegetables, meat and fish, and milk, cheese and eggs all contributed substantially to the water used to produce avoidable food waste.

    “Fruits and vegetables, meat and fish, and milk, cheese and eggs all contributed substantially to the water used to produce avoidable food waste.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The total average household value of avoidable food waste was $18.01 per week, or $936.52 per year.

    “The total average household value of avoidable food waste was $18.01 per week (Table 3), or $936.52 per year.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The average household wasted 3,366 kcal per week, or 175,032 kcal annually.

    “The average household wasted 3,366 kcal per week (Table 4) or the equivalent of 175,032 kcal annually.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Fruits and vegetables represented more than 50% of the total cost of avoidable food waste, a lower proportion than their share of total weight.

    “Fruits and vegetables represented a lower proportion of total cost than they did of total weight, although they still represented more than 50% of the total cost of avoidable food waste.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    People who bought high volumes of food or who bought a high diversity of items generated more wasted food.

    “People who bought high volumes of food or who bought a high diversity of items generated more wasted food.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    The avoidable food waste generated by a household represented 5,000 liters of water use weekly and 260,000 liters annually.

    “This means that the avoidable food waste generated by a household represented 5,000 liters of water use weekly and 260,000 liters annually.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In this sample, wasted fruits and vegetables contributed 62% of wasted fiber, 48% of wasted magnesium, 85% of wasted vitamin A and 96% of wasted vitamin C.

    “In this sample, wasted fruits and vegetables contributed 62% of wasted fiber, 48% of wasted magnesium, 85% of wasted vitamin A and 96% of wasted vitamin C.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Avoidable household food waste is a substantial contributor to global heating, inefficient agricultural land use, and water loss.

    “Our analysis reveals that avoidable household food waste is a substantial contributor to global heating, inefficient agricultural land use, and water loss.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Daily value suggestions have been calculated for infants (aged 6 months to 1 year), children (aged 1 to 4 years) and adults (any other case).

    “Daily value suggestions have been calculated for infants (aged 6 months to 1 year), children (aged 1 to 4 years) and adults (any other case) (40).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [40] Nutrition Labelling. Table of Daily Values2016

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Self-report methods such as surveys and diaries can be unreliable and tend to underestimate food waste generation.

    “research shows that such observational methods can be unreliable and tend to underestimate food waste generation (17–19).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [17] Quested, 2011, Food and drink waste from households in the UK, Nutr Bull. source

      Not checked in the free run.

    • cites [18] Delley, 2017, Food waste within Swiss households: A segmentation of the population and suggestions for preventive measures, Resour Conserv Recycl. source

      Not checked in the free run.

    • cites [19] Giordano, 2018, Are questionnaires a reliable method to measure food waste?, A pilot study on Italian households. Br Food J. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Eligibility for the study required that families have at least one child between 2 to 8 years of age and that parents have no prior nutrition or food training.

    “Eligibility for this study required that families have at least one child between 2 to 8 years of age and that parents have no prior nutrition or food training.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Auditors identified and weighed each individual food item found in any of the three streams.

    “Auditors identified and weighed each individual food item found in any of the three streams.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    The 2017 and 2018 sub-samples had comparable total mean weights of avoidable food items, so they could be combined for subsequent analysis.

    “We compared the total mean weights of the 2017 and 2018 sub-samples using a Mann-Whitney test and found that these were comparable sub-groups that could be combined for subsequent analysis.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The Water Footprint Network has created water usage databases for crops (43) and animal products (44).

    “They have created water usage databases for crops (43) and animal products (44) that are accessible for use and interpretation.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [43] Mekonnen, 2010

      Not checked in the free run.

    • cites [44] Mekonnen, 2010, The Green, Blue and Grey Water Footprint of Farm Animals and Animal Products,Value of Water Research Report Series No. 48.

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Clune et al. (41) provide GWP estimates for over 150 food categories, converted to a common benchmark of 'farm to regional distribution center'.

    “An LCA meta-analysis study conducted by Clune et al. (41) contains GWP estimations for over 150 food categories. This paper outlines estimations of the kg of CO2 produced per kg of edible food product. The authors convert the various boundaries of the LCA studies to a common benchmark of “farm to regional distribution center” (41).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [41] Clune, 2017, Systematic review of greenhouse gas emissions for different fresh food categories, J Clean Product. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    The avoidable and possibly avoidable categories were aggregated for analysis.

    “Our focus for this paper is on food that could have been eaten, and so we aggregated the avoidable and possibly avoidable categories.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    All three waste streams (garbage, recycling, and organic waste) were collected.

    “All three waste streams were collected, including source-separated organics, recycling, and residual garbage.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    Data was collected from 54 families in 2017 and 40 families in 2018, for a total of 94 participating households.

    “Data was collected from 54 families in 2017 and 40 families 2018, for a total of 94 participating households.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    A total of 94 families with young children living in Guelph, Ontario participated in the study.

    “A total of 94 families with young children living in Guelph, Ontario chose to participate in this study.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    Waste was categorized into six broad categories adapted from the WRAP Household Food Waste Collections Guide.

    “Waste was categorized into six broad categories based on the criteria used by the Guelph Food Waste Research Group in previous work in Guelph. These categories were adapted from WRAP Household Food Waste Collections Guide1.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites WRAP Household Food Waste Collections Guide1

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Health Canada suggests that adults and youth (age 13 and older) require approximately 2,000 kcal per day and children (ages 4-12) need 1,500 kcal per day.

    “Health Canada suggests that on average, adults and youth (age 13 and older) require approximately 2,000 kcal per day and children (ages 4–12) need 1,500 kcal per day (39).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [39] Dietary Reference Intake Tables2006

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The household waste audits were conducted over four consecutive weeks in 2017 and three consecutive weeks in 2018 over the summer.

    “The household waste audits were conducted over four consecutive weeks in 2017 and three consecutive weeks in 2018 over the summer.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Nijdam et al. (42) provide midrange land use values for protein-rich food items.

    “Using the midrange values from Table 3 in Nijdam et al. (42), we estimated the land usage of the remaining protein-rich food items found in our audits.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [42] Nijdam, 2012, The price of protein: Review of land use and carbon footprints from life cycle assessments of animal food products and their substitutes, Food Policy source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The study was conducted in accordance with the University of Guelph's Research Ethics Board protocols.

    “This study took place in the city of Guelph, Ontario, and was conducted in accordance with the University of Guelph's Research Ethics Board protocols.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Health Canada reports that among adults, inadequate intakes are highest for vitamin A, vitamin D, magnesium and calcium, with additional concern for vitamin B12, fiber and vitamin C.

    “According to Health Canada, the prevalence of inadequate intakes among adults is highest for vitamin A, vitamin D, magnesium and calcium. Of additional concern are vitamin B12, fiber and vitamin C (37).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [37] Do Canadian Adults Meet their Nutrient Requirements through Food Intake Alone?2012

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    Differences in data collection methods, food preferences, shopping habits and definitions of edibility may account for the different results between this study and Cooper et al. (16).

    “Differences in data collection methods, food preferences, shopping habits and definitions of edibility may account for these different results.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The very high rates of avoidable fruit and vegetable waste have environmental and economic implications.

    “The very high rates of avoidable fruit and vegetable waste also have environmental and economic implications, as noted in Table 6.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    The difference in value between the study estimate and the Metro Vancouver estimate is likely attributable to food cost differences between Vancouver and Guelph.

    “The difference in value is likely attributable to food cost differences between Vancouver and Guelph.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationown data

    More expensive items appear to be managed with more care and wasted less in this sample.

    “One would expect that more expensive items would be managed with more care and be wasted less, which appears to be the case in our sample.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Another commonly cited value for food waste in Canada is $28 per week.

    “Another commonly cited value for food waste in Canada is $28 per week”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [56] MartinRC A Case for Reducing Food Waste2019

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The average household could have provisioned an additional five adult meals or almost seven child meals per week based on the edible items they wasted.

    “In other words, the average household could have provisioned an additional five adult meals or almost seven child meals per week based on the edible items they wasted.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The sample of households audited generated similar amounts of food waste to a more extensive sample in the same locale (Parizeau et al. 14), and similar food group proportions were observed in a randomly-selected sample from Guelph.

    “Overall, the sample of households that we audited in this study generated similar amounts of food waste to a more extensive sample in the same locale, discussed in Parizeau et al. (14), and similar food group proportions were observed in a randomly-selected sample from Guelph (unpublished data).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [14] Parizeau, 2015, Household-level dynamics of food waste production and related beliefs, attitudes, and behaviours in a municipality in Southwestern Ontario, Waste Manag. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationown data

    Avoidable household food waste can be understood from multiple perspectives, and diverse framings highlight different aspects of the food waste problem.

    “Our analysis has demonstrated that avoidable household food waste can be understood from multiple perspectives, and that diverse framings highlight different aspects of the food waste problem.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The average 5-min shower uses 35 liters of water, which equates to 7,429 showers per year.

    “The average 5-min shower uses 35 liters of water, which equates to 7,429 showers per year (46).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [46] How Much is 100,000 Litres of Water?2016

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The GWP equates to 1.2 tons of carbon dioxide from avoidable food waste per household per year, equivalent to one quarter of the emissions from a car being driven for a year, or 2.8 barrels of oil consumed.

    “This equates to 1.2 tons of carbon dioxide from avoidable food waste per household per year, which is equivalent to one quarter of the emissions from a car being driven for a year, or 2.8 barrels of oil consumed based on a US Environmental Protection Agency calculator (45).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [45] Greenhouse Gas Equivalencies Calculator2018

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The $28 per week estimate was not based on audits and likely included the value of unavoidable waste.

    “but this estimate was not based on audits and likely included the value of unavoidable waste (56).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [56] MartinRC A Case for Reducing Food Waste2019

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The CEC estimate is not based on actual audit measurement of household food waste.

    “However, the CEC estimate is not based on actual audit measurement of household food waste.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [12] Characterization and Management of Organic Waste in North America: Foundational Report2017

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Annual avoidable food waste represents the suggested daily caloric intake for an adult for 88 days of the year, and for a child for 117 days.

    “Annual avoidable food waste represents the suggested daily caloric intake for an adult for 88 days of the year, and for a child for 117 days.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Conrad et al. found that 422 grams of avoidable food waste was generated per day.

    “and that 422 grams of avoidable food waste was generated per day.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [61] Conrad, 2018, Relationship between food waste, diet quality, and environmental sustainability

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Conrad et al. estimated that the average American consumer wasted approximately 5,600 kcal per week.

    “authors estimated that the average American consumer wasted approximately 5,600 kcal per week”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [61] Conrad, 2018, Relationship between food waste, diet quality, and environmental sustainability

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The disconnect in results highlights the value of direct measurement of granular data to quantify both the volume and composition of household food waste.

    “This disconnect in results highlights the value of direct measurement of granular data to quantify both the volume and composition of household food waste.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    Community members may have a greater baseline understanding of food waste reduction strategies than people living in other communities.

    “community members may have a greater baseline understanding of food waste reduction strategies than people living in other communities.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The City of Guelph is active in providing educational content on waste management topics through their website, the distribution of informational material to households, and participation in community events.

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationnone given

    The authors are unaware of any other published studies that have used this methodology with Canadian data, or that base their estimates of food waste impacts on direct observation of individual items in the residential waste stream.

    “We are unaware of any other published studies that have used this methodology with Canadian data, or that base their estimates of food waste impacts on direct observation of individual items in the residential waste stream.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationown data

    The study contributes a highly granular analysis of household food waste composition to the field of waste studies.

    “Methodologically, our study contributes a highly granular analysis of household food waste composition to the field of waste studies.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    This study focused on families with young children who had the time and interest in committing to this study.

    “Rather, this study focused on families with young children who had the time and interest in committing to this study.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Conrad et al. suggest that healthier diets, as measured by the Healthy Eating Index, create more waste.

    “Conrad et al. (61) also suggest that healthier diets, as measured by the Healthy Eating Index, create more waste.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [61] Conrad, 2018, Relationship between food waste, diet quality, and environmental sustainability

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Interpretationnone given

    It is likely that multiple synergistic messages can support one another and allow for discursive framings that are diverse and tailorable for different audiences.

    “It is likely that multiple synergistic messages can support one another and allow for discursive framings that are diverse and tailorable for different audiences.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Interpretationnone given

    There are still diverse and non-coherent discourses at play, and none have become hegemonic at this stage.

    “However, there are still diverse and non-coherent discourses at play, and none have become hegemonic at this stage.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationnone given

    The research problematizes dietary research that relies on purchase records and self-reported consumption logs, but that does not assess the proportion of nutritious food that ends up in waste streams.

    “Our research also problematizes dietary research that relies on purchase records and self-reported consumption logs, but that does not assess the proportion of nutritious food that ends up in waste streams.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    The study requirements may have served as a disincentive for families who were less organized, possibly correlating with poor food planning skills and higher food waste generation.

    “These requirements may have served as a disincentive for families who were less organized, possibly correlating with poor food planning skills and higher food waste generation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    The voluntary nature of participation in this study may have led to some self-selection bias.

    “The voluntary nature of participation in this study may have led to some self-selection bias.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    It is possible that only families with a pre-existing interest in and understanding of food chose to participate.

    “It is possible that only families with a pre-existing interest in and understanding of food chose to participate.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Parizeau et al. found that households with greater "food awareness" generated less organic waste.

    “Parizeau et al. (14) found that households with greater “food awareness” generated less organic waste.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [14] Parizeau, 2015, Household-level dynamics of food waste production and related beliefs, attitudes, and behaviours in a municipality in Southwestern Ontario, Waste Manag. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Cooper et al. attribute 6.1 kg of CO2 from avoidable food waste per capita weekly in the United Kingdom.

    “Cooper et al. (16) attribute 6.1 kg of CO2 from avoidable food waste per capita weekly in the United Kingdom.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [16] Cooper, 2018, Nutrition in the bin: a nutritional and environmental assessment of food wasted in the UK, Frontiers in Nutrition source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Cooper et al. suggest that avoidable food waste used 6.3 cubic meters per person per week.

    “who suggest that avoidable food waste used 6.3 cubic meters per person per week.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [16] Cooper, 2018, Nutrition in the bin: a nutritional and environmental assessment of food wasted in the UK, Frontiers in Nutrition source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Participants were aware that their waste was being audited.

    “Furthermore, participants were aware that their waste was being audited.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    This snapshot of the waste of families with children in Guelph is likely not generalizable to other contexts.

    “We acknowledge that this snapshot of the waste of families with children in Guelph is likely not generalizable to other contexts”
    Quote in the paperNot a substantial claim
75 of 75

  • The paper relies on this without support.

    No other research in Canada systematically records each item of food waste generated at the individual household level.

    “We are unaware of any other research in Canada that systematically records each item of food waste generated at the individual household level”

  • The paper relies on this without support.

    Meat and fish are relatively expensive foodstuffs.

    “Meat and fish are relatively expensive foodstuffs”

  • The paper relies on this without support.

    The list includes very common items in Canadian grocery baskets.

    “The list includes very common items in Canadian grocery baskets”

  • The paper relies on this without support.

    A perennial methodological difficulty when studying household waste is the high variability both within and between households.

    “A perennial methodological difficulty when studying household waste is the high variability both within and between households.”

  • The paper relies on this without support.

    The City of Guelph is active in providing educational content on waste management topics through their website, the distribution of informational material to households, and participation in community events.

    “the City of Guelph is active in providing educational content on waste management topics through their website, the distribution of informational material to households, and participation in community events.”

  • The paper relies on this without support.

    Food waste is a systemic issue.

    “Food waste is a systemic issue”

  • The paper relies on this without support.

    Nutrient-dense but low-calorie foods such as fruits and vegetables are better examined based on their nutritional quality rather than their caloric density.

    “nutrient-dense but low-calorie foods such as fruits and vegetables are better examined based on their nutritional quality rather than their caloric density.”

  • The paper relies on this without support.

    The National Zero Waste Council estimated that an average household wastes more than $1,100 in edible food per year.

    “They estimated that an average household wastes more than $1,100 in edible food per year.”
8 of 8

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • National estimates from the US suggest food losses represent over $161 billion, and at the household level could equate to well over $800-900 USD of lost value per year for families with children.

    “National estimates from the US suggest that food losses represent over $161 billion (US Department of Agriculture, 2014), and at the household level, could equate to well over $800-900 USD of lost value per year for families with children, depending on the method of estimation (Russell, et al., 2017;Massow, et al., 2019).”

    From Waste watchers: A food waste reduction intervention among households in Arizona (2021) · cites this paper as Massow, et al., 2019

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Fruits and vegetables are not the largest source of land use

    Minor

    The land-usage discussion identifies fruits and vegetables as the largest share, but Table 5 assigns breads and cereals 2.4 m2 (35.6%), compared with 2.0 m2 (29.1%) for fruits and vegetables.

  • Summary table misstates the food groups' GWP shares

    Minor

    Table 6 gives meat and fish 24.6% of GWP, whereas Table 5 gives 33.6%. The GWP shares in Table 6 instead repeat its water-use shares, changing the reported breakdown of emissions by food group.

  • Scaling avoidable-waste cost to total waste gives a different value

    Minor

    Using the paper's weekly weights, scaling $18.01 from 2.98 kg of avoidable waste to 4.41 kg of total waste gives approximately $26.65, not $27.29.

3 of 3

The citation lists haven’t been fetched yet

References 30 · Cited by 103

Research works printed but not linked: 1

  1. Mekonnen, 2010, The Green, Blue and Grey Water Footprint of Crops and Deriacved Crop Products, Value of Water Research Report Series No. 47

Authors
von Massow, M., Parizeau, K., Gallant, M., Wickson, M., Haines, J., Ma, D. W. L., Wallace, A., Carroll, N., & Duncan, A. M.
Affiliations
University of Guelph (CA)
Corresponding author
Parizeau, Kate
ORCID
Venue
Frontiers in Nutrition
Publisher
Frontiers Media SA
Published
2019-09-04
Volume
6
Pages
143-143
ISSN
2296-861X (ISSN-L)
DOI
10.3389/fnut.2019.00143
PMC
PMC6738328
OpenAlex
W2969500922
Cited by
103
References
30
Citations by year
2026: 6 · 2025: 15 · 2024: 16 · 2023: 10 · 2022: 24 · 2021: 22 · 2020: 9 · 2019: 1
FWCI
10.80
Type
journal article
Language
en
Open access
Licence
Locations
  • Frontiers in Nutrition (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
Social Sciences and Humanities Research Council of Canada
Topics
  • Life Sciences › Agricultural and Biological Sciences › Food Science › Food Waste Reduction and Sustainability
  • Physical Sciences › Environmental Science › Ecology › Agriculture Sustainability and Environmental Impact
  • Physical Sciences › Environmental Science › Waste Management and Disposal › Waste Management and Recycling
Keywords
household food waste, avoidable food waste, economic losses, nutrient loss, global warming potential, land use, water consumption, food purchasing, organic waste, waste reduction policy

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

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