The ultimate guide to developing environmentally sustainable recipes

Introduction

Christian Reynolds, Senior Lecturer at the Centre of Food Policy, delivered a series of three insightful presentations at various scientific conferences at the end of 2021 and in 2022. These presentations constitute an invaluable resource for anyone interested in evaluating and enhancing the nutritional and environmental aspects of recipes and meals. Reynolds’ first presentation discusses his teams’ pioneering customised recipe assessment tool which is able to identify the environmental impact of current recipes available to consumers. The second presentation takes a closer look at how recipes can be adapted and which type of recipes are most conducive to meeting both nutritional and environmental targets. The final presentation investigates the history and transition of vegetarian recipes and their environmental impact through the centuries to modern times.

These presentations are a manifestation of the ongoing research efforts of Christian Reynolds and his team at the City University of London. They are now readily accessible for download, making these valuable insights accessible to a wider audience. The three presentation show top line results of the carbon footprint of recipes.

1) Comparing the environmental impacts of recipes from four different recipe databases using Natural Language Processing

The first of the three presentations begins with a poster presented at the Livestock, Environment and People (LEAP) Conference in December 2021, where Reynolds introduces the groundbreaking customised tool developed by his team at City University London and its validation. The tool is able to extract and decipher recipe ingredients, quantities and units from digitised recipes in three languages: Dutch, English and German. With this tool, the team was able to identify 220,168 indexed recipes and assess their environmental footprint based on a database of 4,500 ingredients.(1)

This environmental database used was from Poore and Nemecek (2018) – which provided four environmental parameters for each recipe ingredient:

• GHG emissions (kg CO2equiv.)

• Land use (m2)

• Eutrophying Emissions (g PO43-equiv.)

• Stress-weighted water use (L) & freshwater withdrawals (L)

With the newly developed tool, they evaluated the environmental impact of vegan, vegetarian and non-vegetarian recipes available online and compared the tools findings with their manual calculations of 50 recipes found across four websites:

• BBC Good Food (UK)

• Albert Heijn/Allerhande (Dutch)

• AllRecipes.com (English global)

• Kochbar (German).

The poster presents the GHG emissions per portion of a recipe. It highlights that German and omnivore recipes had the biggest GHG emissions whilst vegan recipes had the lowest emissions. They also identified the footprint of the key protein ingredient within recipes and again presenting the information as per portion, identified that beef and pork recipes had the highest footprint whilst beans, tofu and peas had the lowest footprint.

2) How commonly consumed recipes and meals align or can be modified to better align with EAT Planetary Health Diet recommendations

This work was presented at the British Dietetic Association Sustainable Diets Specialist group meeting in June 2022. This presentation builds on Reynolds’ team recipe analysis tool. This presentation focused on their collaboration with Edamam – a database providing the environmental impact of over 2,800 ingredient using the USDA food classification and using Poore and Nemecek 2018 dataset.(2)

Using their recipe assessment tool with Edamam’s dataset they evaluated 196,000 recipes reflecting over 90% of recipes offered by restaurants or meals commonly cooked at home.

To assess the environmental quality of the recipes – the team compared the 196,00 recipes’ GHG emissions (kg CO2 equiv.) to the EAT-PHD recommendations

What are the EAT-PHD recommendations?

Key recommendations per person per day: a max of 1,780g CO2 equivalent emissions, 2,500kcal and 56g protein.

For the assessment, all recipes were scaled up to meet the individual overall EAT-PHD recommendations.

Information was provided as g CO2 equiv. per portion, per kcal and per g protein.

Key findings

Most recipes far exceeded GHG emission EAT-PHD targets with a mean 2,101.5g CO2 equiv. per portion – which is in excess of the individual daily dietary targets.

Just 2.8% (5,619) of recipes fell within the EAT-PHD recommended targets with a mean 181g CO2 equiv. per portion.

Type of recipe dietary pattern influences footprint

Type of dietary pattern of the recipes was highly influential on the footprint of the diets. Recipes following the DASH, vegan or vegetarian dietary patterns provided the lowest footprint at 400-884g CO2 equiv. per portion compared to general eating habits, gluten-free, keto or paleo recipes with footprints of 1,400 up to 4,400g CO2 equiv. per portion.

Main protein ingredient – major determinant of recipe GHG emissions

Additionally, the main type of protein ingredient was also influential, with beef-based meals providing the highest footprint and pea-based meals providing the lowest.

The style of cuisine and meal occasion had little influence on the footprint, highlighting that any cuisine and meal occasion can be made sustainable.

Halving animal protein and replacing with plant protein foods is the single biggest action to lower carbon footprint

When it comes to adapting recipes, the team identified the biggest environmental benefit to be the halving of animal protein and fats and replacing with plant proteins. These adaptations produced the biggest drop in carbon footprint with a reduction of 50%.

3) The evolution of “sustainable” and vegetarian recipes from manuscripts and cookbooks to online

The final presentation in this series focuses on the teams’ exploration of the evolution of vegetarian/plant-based recipes over the centuries and their impact on environmental markers. This was presented at the Amsterdam Symposium on the History of Food in February 2022 and the work tracked changes in ingredients, methods, and environmental impacts of recipes over time. It reviewed recipe books from 1600s right through to current times and digital formats. There has been a clear shift from books advocating vegetarian diets with a focus on beans and pulses to more recent publications focusing specifically on environmental benefits and how to waste less.(3)

Evaluating the footprint of current digital recipes in Europe

Using their groundbreaking assessment tool, the team evaluated the environmental footprint of vegan, vegetarian, and non-vegetarian recipes published on four large online recipe forums in Europe:: Kochbar (German), Albert Heijn (Dutch), BBC Good Food (UK) and AllRecipes (global-English).

Setting a GHG emission target per portion of a recipe

The team set a benchmark for GHG emissions that should be contributed by a serving of a meal in order to ensure daily dietary GHG emissions were within the planetary boundaries.

They used the EAT-PHD recommendations to set their target. The EAT-PHD dietary GHG emission target of no more than 1,780g CO2 equiv. per person per day was divided by three to provide the target dietary GHG emission that should be provided per meal serving – based on an individual consuming three meals daily.

Thus the target was set at no more than 590g CO2 equiv. per serving of a recipe/meal.

Median CO2 equiv. of current recipes exceed targets for keeping within planetary boundaries

Similar to their previous presentation, the median CO2 equiv. per portion of current online recipes all exceed the EAT-PHD recommendations, with per recipe portion values of 1,351g CO2 equiv. from Kochbar site, 748g CO2 equiv. for recipes on the Albert Heijn site and 685g CO2 equiv. for recipes on the BBC Good Food. However, the AllRecipes website provided a median of 130g CO2 equiv. per serving.

Vegan recipes superior for environmental footprint

When analysing vegan, vegetarian and omnivore recipes separately, vegan recipes were the only ones which met the target 108g CO2 equiv. per portion. Vegetarian diets exceeded the target by 37% at 811g CO2 equiv. per serving and meat recipes were three times the target emissions at 1,727g CO2 equiv. per portion.

Tofu recipes provided up to 63 times fewer GHG emissions compared to beef based dishes.

In summary

Recipe design should prioritize adherence to EAT-PHD recommendations, aiming to keep carbon emissions below 590g CO2 equiv. per portion. While only vegan diets consistently meet this target, there's room for improvement in planning vegetarian and meat-inclusive recipes to approach these lower thresholds. It's crucial to recognize that our diets are diverse, with meal patterns varying daily. Consequently, meals with higher greenhouse gas emissions should be consumed less frequently, balancing out the overall weekly contribution of dietary emissions.

To download the presentations and find out more, click on the links below.

1. Comparing the environmental impacts of recipes from four different recipe databases using Natural Language Processing

2. How commonly consumed recipes and meals align or can be modified to better align with EAT Planetary Health Diet recommendations

3. The evolution of “sustainable” and vegetarian recipes from manuscripts and cookbooks to online

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