We studied to what extent plant-based meat substitutes could improve the nutritional adequacy and healthiness of dietary patterns, depending on their nutrient composition. From diets observed in French adults (INCA3, n = 1125), modeled diets were identified by allowing various dietary changes, between and within food categories, when two plant-based meat substitutes were made available: an average substitute (from 43 market substitutes) and a theoretical nutritionally designed substitute, fortified or not with zinc and iron at 30

BackgroundAnimal and plant protein sources have contrasting relationships with nutrient adequacy and long-term health, and their adequate ratio is highly debated.ObjectiveWe aimed to explore how the percentage of plant protein in the diet (%PP) relates to nutrient adequacy and long-term health but also to environmental pressures, to determine the adequate and potentially optimal %PP values.MethodsObserved diets were extracted from the dietary intakes of French adults (INCA3, n = 1,125). Using reference values for nutrients and disease burden risks for foods, we modeled diets with graded %PP values that simultaneously ensure nutrient adequacy, minimize long-term health risks and preserve at best dietary habits. This multi-criteria diet optimization was conducted in a hierarchical manner, giving priority to long-term health over diet proximity, under the constraints of ensuring nutrient adequacy and food cultural acceptability. We explored the tensions between objectives and identified the most critical nutrients and influential constraints by sensitivity analysis. Finally, environmental pressures related to the modeled diets were estimated using the AGRIBALYSE database.ResultsWe find that nutrient-adequate diets must fall within the ~15–80% %PP range, a slightly wider range being nevertheless identifiable by waiving the food acceptability constraints. Fully healthy diets, also achieving the minimum-risk exposure levels for both unhealthy and healthy foods, must fall within the 25–70% %PP range. All of these healthy diets were very distant from current typical diet. Those with higher %PP had lower environmental impacts, notably on climate change and land use, while being as far from current diet.ConclusionThere is no single optimal %PP value when considering only nutrition and health, but high %PP diets are more sustainable. For %PP > 80%, nutrient fortification/supplementation and/or new foods are required.

Shifts in dietary patterns are important for both health and the environment, and ruminant meat has been highlighted as a critical cornerstone in this respect. Here, nonlinear and multi-objective diet optimization based on the consumption of French adults (INCA3, n = 1 125, 18-64 years old) have been used to model transitions towards nutritionally adequate and healthy dietary patterns under scenarios of either the direct removal or gradual reduction (in 10% steps) of ruminant meat, without or with preserving at best dietary habits, respec-tively. This has led to identify the nutritional issues when designing diets low in ruminant meat, and the dietary levers that make them nutritionally adequate and healthy. Overall, our main finding is that ruminant meat could readily be replaced by poultry. Such a gradual transition from ruminant meat to poultry should be accompanied by an in-depth restructuring to achieve a healthy diet, involving the early removal of processed meat and non -ruminant red meat and a gradual increase in healthy plant-based foods such as fruits and vegetables (reaching 800 g/d at the final step) and whole grain products (reaching 330 g/d). In terms of its expected environmental impacts, this transition would result in a gradual improvement in greenhouse gas emissions and land use (up to-29% and-36%, respectively), without changing cumulative energy demand but requiring an increase in water use (up to +47%). Finally, reducing ruminant meat forms part of a transitional feature that consists in replacing all red meat with poultry, which could result in healthy and nutritionally adequate dietary patterns aligned with reductions in greenhouse gas emissions.

BACKGROUND:Much effort has been devoted to defining healthy diets, which could lower the burden of disease and provide targets for populations. However, these target diets are far removed from current diets, so at best, the population is expected to move slowly along a trajectory. OBJECTIVE:Our aim was to characterize the different possible trajectories toward a target diet and identify the most efficient one for health to point out the first dietary changes being the most urgent to implement. METHODS:Using graph theory, we have developed a new method to represent in a graph all stepwise change trajectories toward a target healthy diet, with trajectories all avoiding risk of nutrient deficiency. Then, we have identified and characterized the trajectory with the highest value for long-term health. Observed male and female average diets are from the French representative survey INCA3, and target diets were set using multicriteria optimization. The best trajectories were found using the Dijkstra algorithm with the Health risk criteria based on epidemiological data. RESULTS:Within ∼2.6M diets in the graphs, we found optimal trajectories that were rather similar for males and females regarding the most efficient changes in the first phase of the pathways. In particular, we found that a 1-step increase in the consumption of whole/semirefined bread (60 g) was the first step in all healthiest trajectories. In males, the subsequent decrease in red meat was immediately preceded by increases in legumes. CONCLUSIONS:We show simple practical dietary changes that can be prioritized along an integral pathway that is the most efficient overall for health when transiting toward a distant healthy diet. We put forward a new method to analyze dietary strategy for public health transition and highlight the first critical steps to prioritize.

Diets rich in plant-based foods are encouraged for human health and to preserve resources and the environment but the nutritional quality and safety of such diets is debated. This study aimed to model nutritionally adequate diets with increasing plant food content and to characterise the derived diets using a multicriteria approach including, nutrients intake, environmental pressures and exposure to pesticides. Using data of the NutriNet-Santé cohort (N = 29,413), we implemented stepwise optimization models to identified maximum plant-food content under nutritional constraints. Environmental indicators at the production level were derived from the DIALECTE database, and exposure to pesticide residues from plant food consumption was estimated using a contamination database. Plant-based foods contributed to 64.3% (SD = 10.6%) of energy intake in observed diets and may reach up to 95% in modelled diets without jeopardizing nutritional status. Compared to the observed situation, an increase in plant-based foods in the diets led to increases in soy-based products (+ 480%), dried fruits (+ 370%), legumes (+ 317%), whole grains (+ 251%), oils (+ 144%) and vegetables (+ 93%). Animal products decreased progressively until total eviction, except for beef (− 98%). Dietary quality (estimated using the Diet Quality Index Based on the Probability of Adequate Nutrient Intake) was improved (up to 17%) as well as GHGe (up to − 65%), energy demand (up to − 48%), and land occupation (− 56%) for production. Exposures to pesticides from plant-based foods were increased by 100% conventional production and to a much lesser extent by 100% organic production. This study shows that shifting to nutritionally-adequate plant-based diets requires an in-depth rearrangement of food groups’ consumption but allows a drastic reduction environmental impact. Increase exposure to pesticide residues and related risks can be mitigated by consuming foods produced with low pesticide input.

BACKGROUND & AIMS:Reducing meat consumption is a current trend and a strong prospect for the future in Western countries, but its dietary modalities and nutrient challenges remain poorly documented. Using diet optimization under a broad set of constraints, we tried to identify a sequential meat reduction transition and analyze its nutrient issues and dietary levers. METHODS:Based on the consumption of French adults (INCA3, n = 1 125, 18-64 years old), we modeled a transition towards a nutritionally adequate healthy dietary pattern under the constraint of a gradual reduction in meat consumption in successive 10% steps. Using a multi-criteria optimization procedure, the diet modeled at each meat reduction step was to be healthier but close to the previous diet. RESULTS:The most significant changes occurred early in the modeled transition process, with drastic reductions in processed and red meats in favor of poultry, which rapidly became the predominant meat before gradually decreasing from 50% to 100% meat reduction. At the same time, whole grain products, fruits and vegetables consumption increased rapidly to reach a plateau from 50% meat reduction onwards. Some nutrients were limiting, in particular bioavailable iron and zinc, and vitamin A, but sufficient intakes were achieved by restructuring diets based on food groups other than meat. Other nutrients mainly supplied by meat such as vitamin B6 and B12, protein and indispensable amino acids, were never limiting. CONCLUSION:Healthy and nutritionally adequate food patterns can be identified throughout a transition to complete meat reduction. After a 50% reduction in meat consumption, poultry is almost the only meat remaining and its further reduction makes the diet only marginally healthier.

Background: Research has shown that vegetarian diets have a low environmental impact, but few studies have examined the environmental impacts and nutritional adequacy of these diets together, even though vegetarian diets can lead to nutritional issues. Objectives: Our objective was to optimize and compare 6 types of diets with varying degrees of plant foods (lacto-, ovolacto-, and pescovegetarian diets and diets with low, medium, and high meat content) under nutritional constraints. Methods: Consumption data in 30,000 participants were derived from the French NutriNet-Sante cohort using an FFQ. Diets were optimized by a nonlinear algorithm minimizing the diet deviation while meeting multiple constraints at both the individual and population levels: nonincrease of the cost and environmental impacts (as partial ReCiPe accounting for greenhouse gas emissions, cumulative energy demand, and land occupation, distinguishing production methods: organic and conventional), under epidemiologic, nutritional (based on nutrient reference values), and acceptability (according to the diet type) constraints. Results: Optimized diets were successfully identified for each diet type, except that it was impossible to meet the EPA (20:5n-3) + DHA (22:6n-3) requirements in lacto- and ovolactovegetarians. In all cases, meat consumption was redistributed or reduced and the consumption of legumes (including soy-based products), whole grains, and vegetables were increased, whereas some food groups, such as potatoes, fruit juices, and alcoholic beverages, were entirely removed from the diets. The lower environmental impacts (as well as individual indicators) observed for vegetarians could be attained even when nutritional references were reached except for long-chain n-3 (omega-3) fatty acids. Conclusions: A low-meat diet could be considered as a target for the general population in the context of sustainable transitions, although all diets tested can be overall nutritionally adequate (except for n-3 fatty acids) when planned appropriately.

Background Scientific literature about environmental pressures associated with dietary patterns has been considerably growing over the last decade. However, few studies have analyzed the environmental impacts associated with the consumption of ultra-processed food (UPF) and which steps of the food system that contribute most to environmental pressures. The objective of this study was to investigate, in a representative sample of the adult French population, the environmental pressures of diets according to UPF consumption. Methods The study was conducted in 2,121 adults of the French nationally representative survey INCA 3. Food intakes were analyzed to define the %UPF (in weight) in the diet according to NOVA classification. Using detailed environmental data of foods of Agribalyse, we could assess the contribution of UPF to 14 indicators of environmental pressure and details those related to the stage of the food consumed: production, processing, storage, packaging, transport and retailing at the food level. The data was described according to quintiles of % of UPF in the diet and analyzed using crude and energy-adjusted models. Results Compared to low consumers of UPF (Q1, median UPF= 7%), high consumers (Q5, median UPF= 35%) had a higher energy intake (+22%) which came along with different environmental pressures (e.g. +15% greenhouse gas emissions (GHGe), +17% land use, -7% water use and +8% cumulative energy demand). Higher pressures could be ascribed to higher energy. However, the processing and packaging stages were significant contributor to energy demand. In Q5, contributions of the UPF category to total pressure were 35%, 39%, 28% and 42% for GHGe, water use land use, and energy demand, respectively, while ranging from 11 to 15% in Q1. Conclusions Diets rich in UPF, compared to low, were overall associated with intensification in GHGe, land use, and energy demand and with higher contribution of post-farm stages, in particular processing regarding energy demand. Highlights ### Competing Interest Statement FM was the scientific leader of a PhD project funded until October 2021 in part by a research contract with Terres Univia, the French Interbranch organization for plant oils and proteins. The other authors declared no conflict of interest. ### Funding Statement none ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study used public french data from the INCA study 3 : https://www.data.gouv.fr/fr/datasets/donnees-de-consommations-et-habitudes-alimentaires-de-letude-inca-3/. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Data availability: Data described in the manuscript are available at: https://www.data.gouv.fr/fr/datasets/donnees-de-consommations-et-habitudes-alimentaires-de-letude-inca-3/.

While consumer demand for meat substitutes is growing, their varied composition raises questions regarding their nutritional value. We aimed to identify and characterize the optimal composition of a meat substitute that would best improve diet quality after complete meat replacement. From an average individual representing the dietary intake of French adults (INCA3, n = 1125), meat was replaced with an equivalent amount of a mostly pulse-based substitute, whose composition was based on a list of 159 possible plant ingredients and optimized non-linearly to maximize diet quality assessed with the PANDiet score (considering adequacy for 32 nutrients), while taking account of technological constraints and applying nutritional constraints to limit the risk of overt deficiency in 12 key nutrients. The optimized meat substitute contained 13 minimally processed ingredients. When used to substitute meat, the PANDiet score increased by 5.7 points above its initial value before substitution (versus − 3.1 to + 1.5 points when using other substitutes on the market), mainly because of higher intakes of nutrients that are currently insufficiently consumed (e.g., alpha-linolenic acid, fiber, linoleic acid) and a lower SFA intake. The meat substitute also mostly compensated for the lower provision of some indispensable nutrients to which meat greatly contributed (e.g., vitamin B6, potassium, bioavailable iron), but it could not compensate for bioavailable zinc and vitamin B12. Choosing the correct ingredients can result in a nutritionally highly effective meat substitute that could compensate for reductions in many nutrients supplied by meat while providing key nutrients that are currently insufficiently consumed.

Our recognition of the environmental pressures associated with dietary patterns has grown considerably over the past decade. However, few studies have analysed the impacts associated with the consumption of ultra-processed food (UPF) and which steps in the food chain contribute the most. Here, using a representative sample of French adults (2,121 enrolled in the Third French Individual and National Food Consumption survey), we investigate the environmental pressures of diets according to UPF consumption. Food intakes were analysed to define the %UPF by weight in the diet according to the NOVA food-classification system. Using detailed environmental data from Agribalyse, we assessed the contribution of UPF to 14 environmental pressure indicators and the contributions of the different food chain stages to these impacts: production, processing, storage, packaging, transport and retailing. The data were described according to quintiles of %UPF in the diet and analysed using crude and energy-adjusted models. Overall, UPF represented 19% of the diet yet contributed 24% to the diet’s greenhouse gas emissions, 23% to water use, 23% to land use and 26% to energy demand. Compared with low consumers of UPF (quintile 1; median UPF, 7%), high consumers (quintile 5; median UPF, 35%) consumed more caloric energy (+22%). Caloric intake partially explained the higher environmental pressures from high-UPF consumers. After we adjusted for calories consumed, the associations with greenhouse gas emissions and land use vanished, and the associations with water use and energy demand became negative. However, the processing and packaging stages contributed significantly to energy demand. Post-farm stages, such as final-product creation and packaging, contributed greater environmental impacts of UPF-rich diets.

We aimed to study if, and to what extent, the current nutrient reference values for bioavailable iron and zinc limit the identification of healthier dietary patterns. Using observed diets from a representative French survey (INCA3) and multi-criteria optimization, we identified diets that comply with all nutrient reference values and maximize a health criteria based on food-based dietary guidelines while minimally departing from the observed diet. Nutrient reference values included absorbed iron and zinc. This non-linear diet optimization problem was solved in men and women with higher (Fe−) and lower (Fe+) iron requirements separately, either strictly (Non Flexible model, NF) or by allowing some tolerance on absorbed iron and zinc using goal programming to minimize their decreases below reference values (Flexible Model, F). Using a comparative risk assessment framework and a probabilistic approach, we estimated changes in risks of cardiovascular diseases, diabetes and colorectal cancer, and changes in estimates of the prevalence of iron-deficiency anemia for the diets optimized using each model. With the NF model, the reference values for absorbed iron and zinc were the most binding constraints (over 34 constraints). Compared to the observed diets, the NF-optimized diets showed large redistributions within cereals and meats, with total meat consumption remaining similar in men and Fe- women and doubling in Fe + women. In contrast, the F-optimized diets had higher value for the health criteria objective, being systematically lower in meat, especially red meat, and higher in whole grain products. We estimated that the reduction in mortality risk would be 17.7% wih the NF-optimized diets and 21.5% with the F-optimized diets. However, the later diets would increase the prevalence of iron-deficiency anemia from 2.1% currently to 5.6%. We evidenced that the reference values for iron and zinc with regard to their bioavailability are critical factors when modelling healthy eating patterns. Considering lower references for iron and zinc leads to identify diets with an apparent higher benefit for the population health with regards long-term health. None.

Background: Diet-related greenhouse gas emissions (GHGe) mainly comes from animal-sourced foods. As progressive changes are more acceptable for a sustainable food transition, we aimed to identify nutritionally adequate and culturally acceptable optimized diets ensuring a gradual reduction in GHGe, using observed diet from a large sample of French adults, while considering the mode of food production (organic vs conventional farming) and the co-production link between milk and beef. Material and method: Based on the consumption of 257 organic and conventional foods among 29,413 participants (75% women, age: 53.5 +/- 14.0y) of the NutriNet-Sante study, we modelled optimal diets according to GHGe reduction scenarios in 5% steps, from 0 to 50% with nutritional, acceptability, and coproduct constraints, for men, premenopausal and menopausal women separately. Results: Gradual GHGe decrease under these constraints led to optimal diets with an overall decrease in animal foods, with marked reductions in dairy products (up to -83%), together with a stable but largely redistributed meat consumption in favor of poultry (up to +182%) and pork (up to +46%) and at the expense of ruminant meat (down to -92%). Amounts of legumes increases dramatically (up to +238%). The greater the reduction in diet-related GHGe, the lower the cumulative energy demand (about -25%) and land use (about -43%). The proportion of organic food increased from-30% in the observed diets to-70% in the optimized diets. Conclusion: Our results suggest that meeting both nutrient reference value and environmental objectives of up to 50% GHGe reduction requires the reduction of animal foods together with important substitutions between animal food groups, which result in drastic reductions in beef and dairy products. Further research is required to explore alignment with long-term health value and conflict with acceptability, in particular for even greater GHGe reductions. (c) 2021 Elsevier B.V. All rights reserved.

Background: Healthier dietary patterns involve more plant-based foods than current Western diets rich in animal products containing high amounts of bioavailable iron and zinc. Little consideration is given to the bioavailability of iron and zinc when studying healthy eating patterns. Objectives: Our aim was to determine whether currently estimated requirements for bioavailable iron and zinc limit the identification of healthier dietary patterns. Methods: Using dietary data from a representative French survey and multicriteria nonlinear optimization, we identified diets that maximize health criteria based on food-based dietary guidelines and concomitantly depart only minimally from the observed diet while complying with all nutrient reference values either strictly (nonflexible optimization) or by allowing bioavailable iron and zinc below the current reference values, but to a limited extent (flexible optimization). Using a comparative risk assessment model, we estimated the resulting impact on cardiometabolic and colorectal cancer mortality/morbidity and changes to iron-deficiency anemia. Results: Under nonflexible optimization, reference values for bioavailable iron and zinc were the most binding of the 35 nutrient constraints, and modeled diets displayed considerable redistributions within grains and meat. With flexible optimization, modeled diets were healthier as they contained less red meat and more wholegrain products, but would increase iron-deficiency anemia to 5.0% (95% CI: 3.9%, 6.4%). Globally, in terms of disability adjusted life years (DALYs), as the loss due to anemia would represent <30% of the gain otherwise made on chronic diseases, adding flexibility in the iron and zinc reference values would result in a further 18% decrease in the disease burden from 84,768 [95% uncertainty interval (UI): 81,066. 88,470] to 99,689 (95% UI: 95,787, 103,591) DALYs averted. Conclusions: Currently estimated requirements for bioavailable iron and zinc proved to be critical factors when modeling healthy eating patterns. Considering lower reference values enables the identification of diets that are apparently healthier overall.

While consumers’ demand is growing, meat substitutes have much varied composition, raising questions about their nutritional interest. We aimed to identify the composition of a meat substitute that would best improve diet quality, and analyze the impact on nutrient adequacy. We aimed at maximizing the overall diet quality of an average individual representing the nutrient intake of the French adult population (INCA3, n = 1125) by modeling the composition of a meat substitute intended to replace meat, using non-linear optimization (using SAS, proc optmodel). The diet quality was assessed using the PANDiet scoring system, which assesses the probability of adequate nutrient intake. Nutritional constraints were applied in order to not increase the risk of overt deficiency for 12 nutrients. A list of 159 ingredients was used to compose the meat replacer and technological constraints were defined so as to take into account the feasibility of the formulation. The impacts on diet quality of the modelled meat substitute were analyzed and compared with those of 43 meat substitutes on the market. The optimized meat substitute was composed of 13 ingredients (such as coco bean, yellow sweet pepper, rapeseed oil, dried shiitake mushroom, wheat bran and thyme) and this formulation proved to be relatively robust to variations in the model constraints, as shown by a sensitivity analysis. Meat substitution with this optimized meat substitute largely increased the PANDiet, by 5.5 points above its initial value before substitution (73.7/100). In particular, it led to better adequacies for nutrients that are currently insufficiently consumed (e.g., alpha-linolenic acid, fiber, linoleic acid). It also allowed to compensate for loss of some nutrients partly provided by meat (e.g., vitamin B6, potassium and, to a certain extent, bioavailable iron), but was not sufficient to compensate for bioavailable zinc and vitamin B12. The optimized meat substitute proved to be dramatically more nutritionally efficient than the available meat substitutes, whose individual impact on the PANDiet ranged from −3.1 to +1.5 points. We proved that it is possible to select appropriate ingredients resulting in a meat substitute that could be a fairly good nutritional lever when substituting meat. Partly funded by a PhD fellowship from Terres Univia.