Environmental pressures and pesticide exposure associated with an increase in the share of plant-based foods in the diet.

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.

Nutritional and health benefits and risks of plant-based substitute foods.

Plant-based substitutes (PBS) are seen as a convenient way to transition to a more plant-based diet, but their potential health benefits and nutritional concerns remain debated. Based on a review of the literature, it is concluded here that the primary risk of insufficient nutrient intake with PBS concerns iron and calcium, which are critical to the nutritional value of PBS. Other risks were identified but these would depend on the characteristics of the overall diet, as is the case for iodine in a diet containing no seafood or dairy, and vitamin B12 in a vegetarian/vegan diet. Conversely, the use of PBS is also expected to confer some benefits for long-term health because it would result in higher fibre intakes (in the case of meat PBS) and lower SFA intakes (but higher PUFA/MUFA intakes), but attention should be paid to a potential increase in sodium intake with PBS of meat products. In fact, a recurring finding in this review was that PBS is a very heterogeneous food category involving considerable variations in ingredient and nutrient composition, and whose design could be improved in order to foster nutritional and health benefits. The latter also depend on the animal food that is being replaced and are only deemed likely when PBS replace red meat. The fortification of PBS with key nutrients such as iron and calcium may constitute an actionable public health solution to further shift the balance in favour of PBS in the context of the current dietary transition in western countries.

The nature of protein intake as a discriminating factor of diet sustainability: a multi-criteria approach.

Animal production is responsible for 56-58% of the GHG emissions and limiting meat consumption would strongly contribute to reducing human health risks in Western countries. This study aimed to investigate the nature of protein intake as a discriminating factor for diets' sustainability. Using data from 29,210 French adults involved in the NutriNet-Santé cohort, we identified clusters according to 23 protein sources. A multicriteria (environmental, economic, nutritional and health) sustainability analysis was then conducted on the identified clusters. The economic analysis focused on both food and protein expenditure structures, using a budget coefficient approach. Relative values of clusters compared to the whole sample were calculated. We identified five clusters: milk-based, meat-based, fast food-based, healthy-fish-based, and healthy-plant-based. We found that the healthy-plant-based and healthy-fish-based clusters were the most sustainable, conciliating the compromise between human health (0.25 and 0.53 respectively for the Health Risk Score) and the protection of the environment (- 62% and - 19% respectively for the pReCiPe indicator). Conversely, the highest environmental impacts (+ 33% for the pReCiPe indicator) and the highest health risk (0.95 for the HRS) were observed for the meat-based cluster, which was associated with the lowest nutritional scores (- 61% for the PNNS-GS2 score). The economic analysis showed that the healthy-plant-based cluster was the one with the highest food budget coefficient (+ 46%), followed by the healthy-fish-based cluster (+ 8%), partly explained by a strong share of organic food in the diet. However, the meat-based cluster spent more of their food budget on their protein intake (+ 13%), while the healthy-plant-based cluster exhibited the lowest expenditure for this intake (- 41%). Our results demonstrate that the nature of protein intake is a discriminating factor in diet sustainability. Also, reducing animal protein consumption would generate co-benefits beyond environmental impacts, by being favorable for health, while reducing the monetary cost associated with protein intake.

Plant to animal protein ratio in the diet: nutrient adequacy, long-term health and environmental pressure.

Background: Animal and plant protein sources have contrasting relationships with nutrient adequacy and long-term health, and their adequate ratio is highly debated. Objective: We 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. Methods: Observed 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. Results: We 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. Conclusion: There 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.

Identifying the most Efficient Detailed Trajectories toward Healthy Diets-A Graph-Based Analysis.

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.

Ranking food products based on estimating and combining their microbiological, chemical and nutritional risks: Method and application to Ready-To-Eat dishes sold in France.

Microbiological (M), chemical (C), and nutritional (N) risks associated with food products are usually assessed and managed independently by experts in public services or food companies. This can render difficult the comparison of food products in term of overall risk for the consumer. The objective of this study was to suggest a relatively simple method to (i) classify food products based on their M, C and N risks, and (ii) aggregate these risks and rank the food products accordingly. The method was developed and applied to 17 ready-to-eat (RTE) dishes available on the French market. With regard to food safety, the individual M and C risks were characterized considering likelihood and severity as recommended by the Codex Alimentarius. With regard to nutrition/health, the N risk was estimated based on the tendency of the dish to contribute to nutrient adequacy and to a healthy eating pattern. Finally, the outranking method PROMETHEE was applied to aggregate the three M, C, N risks and rank the food dishes. Food products were ranked relatively to each other, not in absolute terms. When we attributed the same weight to M, C and N risks, the RTE dish "Duck Parmentier" had the highest risk score while "Papillote of chicken, potatoes and small vegetables" and "Vegetarian plate vegetables and quinoa" had the lowest. However, this overall ranking changed according to the weight assigned to individual M, C and N risks, at least for food products whose scores varied according to risk types, such as"sushi discovery" (high M and C risks, low N risk). Since the risk ranking method developed here was built with assumptions and hypotheses related to the specific case study, more applications are needed to assess whether it can be generic. Nevertheless, this method is well grounded, objective, transparent, relatively fast and easy to set up. It might lead to further development of decision tools, particularly for consumers. This study paves the way towards food product multi-risk ranking.

Higher adherence to the EAT-Lancet reference diet is associated with higher nutrient adequacy in the NutriNet-Santé cohort: a cross-sectional study.

BACKGROUND: In 2019, the EAT-Lancet Commission proposed a planetary and healthy reference diet; however, its nutritional quality has been rarely evaluated. OBJECTIVE: Across different adherence levels to the EAT-Lancet reference diet, the following were our objectives:1) describe the food and nutritional intakes of the French population, 2) evaluate the nutrient quality, and 3) investigate the consistency between the French national recommendations and the EAT-Lancet reference diet. METHODS: This cross-sectional study was conducted among participants of the NutriNet-Santé cohort, and the sample was weighted on the characteristics of the general French population. Adherence to the EAT-Lancet reference diet was estimated using the EAT-Lancet Diet Index (ELD-I). Usual nutrient intakes were obtained using the variance reduction method. We used the estimated average requirements cut-point method to estimate the proportion of participants who meet their respective nutritional requirements. Furthermore, the adequacy of the French food-based dietary recommendations [Programme National Nutrition Santé (PNNS)] according to adherence to the EAT-Lancet reference diet was studied. RESULTS: The weighted sample was composed of 98,465 participants. Except for bioavailable zinc and vitamin B12, we observed a decrease in the nutrient inadequacy prevalence when the adherence to the EAT-Lancet reference diet increased, particularly for vitamin B9 (Q1 = 37.8% compared with Q5 = 5.5%, P < 0.0001) and vitamin C (Q1 = 59.0% compared with Q5 = 10.8 %, P < 0.0001). However, inadequacy prevalence remained high in all ELD-I quintiles, particularly for fiber (95.9%), vitamin B1 (70.8%), iodine (48.4%), and magnesium (76.8%). Higher ELD-I score was associated with higher adherence for most components of the PNNS, except for food groups that are not specifically included in the EAT-Lancet reference diet and are typical of the French diet, including alcohol, processed meat, and salt. CONCLUSION: In the French context, although issues with the intake of certain nutrients may occur, a diet that remains within the planetary limits as the EAT-Lancet reference diet allows a favorable nutritional quality. This trial was registered at clinicaltrials.gov as NCT03335644.

Plant-based meat substitutes are useful for healthier dietary patterns when adequately formulated - an optimization study in French adults (INCA3).

PURPOSE: We studied to what extent plant-based meat substitutes could improve the nutritional adequacy and healthiness of dietary patterns, depending on their nutrient composition. METHODS: 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% or 50% of Nutrient Reference Values. Under each scenario, healthier but acceptable modeled diets were identified using multi-criteria optimization, by maximizing a health criteria related to Dietary Guidelines while minimizing deviation from the observed diets, under constraints for nutrient adequacy. RESULTS: Without fortification, the average substitute was hardly introduced into modeled diets, whereas the optimized substitute was preferentially introduced, in large amounts, yet together with a moderate reduction of red meat (- 20%). The comparative advantages of the optimized substitute were its higher contribution to vitamins B6 and C, fiber and α-linolenic acid (ALA) intakes, and its lower contribution to sodium intake. When fortified with iron and zinc, substitutes were introduced in larger amounts into modeled diets, with much higher red meat reductions (down to - 90%). The optimized substitute continued to be preferred, leading to healthier modeled diets that deviated less from the observed. CONCLUSION: Plant-based meat substitutes can be levers for healthy diets only when well nutritionally designed with enough zinc and iron for a substantial red meat reduction.

Perspective: Plant-Based Meat Alternatives Can Help Facilitate and Maintain a Lower Animal to Plant Protein Intake Ratio.

The health and environmental advantages of plant-predominant diets will likely lead to increasing numbers of consumers reducing their reliance on animal products. Consequently, health organizations and professionals will need to provide guidance on how best to make this change. In many developed countries, nearly twice as much protein is derived from animal versus plant sources. Potential benefits could result from consuming a higher share of plant protein. Advice to consume equal amounts from each source is more likely to be embraced than advice to eschew all or most animal products. However, much of the plant protein currently consumed comes from refined grains, which is unlikely to provide the benefits associated with plant-predominant diets. In contrast, legumes provide ample amounts of protein as well other components such as fiber, resistant starch, and polyphenolics, which are collectively thought to exert health benefits. But despite their many accolades and endorsement by the nutrition community, legumes make a negligible contribution to global protein intake, especially in developed countries. Furthermore, evidence suggests the consumption of cooked legumes will not substantially increase over the next several decades. We argue here that plant-based meat alternatives (PBMAs) made from legumes are a viable alternative, or a complement, to consuming legumes in the traditional manner. These products may be accepted by meat eaters because they can emulate the orosensory properties and functionality of the foods they are intended to replace. PBMAs can be both transition foods and maintenance foods in that they can facilitate the transition to a plant-predominant diet and make it easier to maintain. PBMAs also have a distinct advantage of being able to be fortified with shortfall nutrients in plant-predominant diets. Whether existing PBMAs provide similar health benefits as whole legumes, or can be formulated to do so, remains to be established.

Compared with Milk Protein, a Wheat and Pea Protein Blend Reduces High-Fat, High-Sucrose Induced Metabolic Dysregulations while Similarly Supporting Tissue Protein Anabolism in Rats.

BACKGROUND: Plant proteins (PPs) have been associated with better cardiovascular health than animal proteins (APs) in epidemiological studies. However, the underlying metabolic mechanisms remain mostly unknown. OBJECTIVES: Using a combination of cutting-edge isotopic methods, we aimed to better characterize the differences in protein and energy metabolisms induced by dietary protein sources (PP compared with AP) in a prudent or western dietary context. METHODS: Male Wistar rats (n = 44, 8 wk old) were fed for 4.5 mo with isoproteic diets differing in their protein isolate sources, either AP (100% milk) or PP (50%:50% pea: wheat) and being normal (NFS) or high (HFS) in sucrose (6% or 15% kcal) and saturated fat (7% or 20% kcal), respectively. We measured body weight and composition, hepatic enzyme activities and lipid content, and plasma metabolites. In the intestine, liver, adipose tissues, and skeletal muscles, we concomitantly assessed the extent of amino acid (AA) trafficking using a 15N natural abundance method, the rates of macronutrient routing to dispensable AA using a 13C natural abundance method, and the metabolic fluxes of protein synthesis (PS) and de novo lipogenesis using a 2H labeling method. Data were analyzed using ANOVA and Mixed models. RESULTS: At the whole-body level, PP limited HFS-induced insulin resistance (-27% in HOMA-IR between HFS groups, P < 0.05). In the liver, PP induced lower lipid content (-17%, P < 0.01) and de novo lipogenesis (-24%, P < 0.05). In the different tissues studied, PP induced higher AA transamination accompanied by higher routings of dietary carbohydrates and lipids toward dispensable AA synthesis by glycolysis and ß-oxidation, resulting in similar tissue PS and protein mass. CONCLUSIONS: In growing rats, compared with AP, a balanced blend of PP similarly supports protein anabolism while better limiting whole-body and tissue metabolic dysregulations through mechanisms related to their less optimal AA profile for direct channeling to PS.

Plant Protein Can Be as Efficient as Milk Protein to Maintain Fat Free Mass in Old Rats, Even When Fat and Sugar Intakes Are High.

BACKGROUND: Alternative, sustainable, and adequate sources of protein must be found to meet global demand. OBJECTIVES: Our aim was to assess the effect of a plant protein blend with a good balance of indispensable amino acids and high contents of leucine, arginine, and cysteine on the maintenance of muscle protein mass and function during aging in comparison to milk proteins and to determine if this effect varied according to the quality of the background diet. METHODS: Old male Wistar rats (n = 96, 18 mo old) were randomly allocated for 4 mo to 1 of 4 diets, differing according to protein source (milk or plant protein blend) and energy content (standard, 3.6 kcal/g, with starch, or high, 4.9 kcal/g, with saturated fat and sucrose). We measured: every 2 mo, body composition and plasma biochemistry; before and after 4 mo, muscle functionality; after 4 mo, in vivo muscle protein synthesis (flooding dose of L-[1-13C]-valine) and muscle, liver, and heart weights. Two-factor ANOVA and repeated measures 2-factor ANOVA were conducted. RESULTS: There was no difference between protein type on the maintenance during aging of lean body mass, muscle mass, and muscle functionality. The high-energy diet significantly increased body fat (+47%) and heart weight (+8%) compared to the standard energy diet but had no effect on fasting plasma glucose and insulin. Muscle protein synthesis was significantly stimulated by feeding to the same extent in all groups (+13%). CONCLUSIONS: Since high-energy diets had little impact on insulin sensitivity and related metabolism, we could not test the hypothesis that in situations of higher insulin resistance, our plant protein blend may be better than milk protein. However, this rat study offers significant proof of concept from the nutritional standpoint that appropriately blended plant proteins can have high nutritional value even in demanding situations such as aging protein metabolism.

Dietary protein consumption profiles show contrasting impacts on environmental and health indicators.

Patterns of protein intake are strong characteristics of diets, and protein sources have been linked to the environmental and nutrition/health impacts of diets. However, few studies have worked on protein profiles, and most of them have focused on specific diets like vegetarian or vegan diets. Furthermore, the description of the environmental impact of diets has often been limited to greenhouse gas emissions (GHGe) and land use. This paper analyzes the alignment of environmental pressures and nutritional impacts in a diversity of representative protein profiles of a western population. Using data from a representative survey in France (INCA3, n = 1125), we identified protein profiles using hierarchical ascendant classification on protein intake (g) from main protein sources (refined grains, whole grains, dairy, eggs, ruminant meat, poultry, pork, processed meat, fish, fruits & vegetables, pulses). We assessed their diet quality using 6 dietary scores, including assessment of long-term risk for health, and associated 14 environmental pressure indicators using the Agribalyse database completed by the SHARP database for GHGe. Five protein profiles were identified according to the high contributions of ruminant meat, pork, poultry, fish, or, conversely, as low contribution from meat. The profile including the lowest protein from meat had the lowest impact on almost all environmental indicators and had the lowest long-term risk. Conversely, the profile with high protein from ruminant-based foods had the highest pressures on most environmental indicators, including GHGe. We found that the protein profile with low contribution from meat has great potential for human health and environment preservation. Shifting a large part of the population toward this profile could be an easy first step toward building a more sustainable diet.

Plasma Metabolome Analysis Suggests That L-Arginine Supplementation Affects Microbial Activity Resulting in a Decrease in Trimethylamine N-oxide-A Randomized Controlled Trial in Healthy Overweight Adults with Cardiometabolic Risk Factors.

Background: The effects of supplementation with L-arginine (L-arg), the precursor of nitric oxide (NO), on vascular and cardiometabolic health have largely been explored. Whether other mechanisms of the action of L-arg exist remains unknown, as arginine metabolism is complicated. Objective: We aimed to characterize the effect of low dose L-arg supplementation on overall human metabolism both in a fasting state and in response to an allostatic stress. Methods: In a randomized, double-blind, crossover study, 32 healthy overweight adults (mean age 45 y) with cardiometabolic risk (fasting plasma triglycerides >150 mg/dL; waist circumference >94 cm [male] or >80 cm [female]) were treated with 1.5 g sustained-release L-arg 3 times/d (4.5 g/d) or placebo for 4 wk. On the last day of treatment, volunteers consumed a high-fat meal challenge (900 kcal, 80% as fat, 13% as carbohydrate, and 7% as protein). Plasma was collected at fasting, 2, 4, and 6 h after the challenge, and the metabolome was analyzed by high-resolution liquid chromatography-mass spectrometry. Metabolic profiles were analyzed using linear mixed models-principal component analysis. Results: The challenge meal explained most of the changes in the metabolome. The overall effect of L-arg supplementation significantly explained 0.5% of the total variance, irrespective of the response to the challenge meal (P < 0.05). Among the metabolites that explain most of the L-arg effect, we found many amino acids, including branched-chain amino acids, that were decreased by L-arg supplementation. L-arg also decreased trimethylamine N-oxide (TMAO). Other changes suggest that L-arg increased methyl demand. Conclusions: Analysis of the effect of 4 wk of L-arg supplementation on the metabolome reveals important effects on methyl balance and gut microbiota activity, such as a decrease in TMAO. Further studies are needed to investigate those mechanisms and the implications of these changes for long-term health.This trial was registered at clinicaltrials.gov as NCT02354794.

Anti-inflammatory Streptococcus thermophilus CNRZ160 limits sarcopenia induced by low-grade inflammation in older adult rats.

Background and aims: Aging is characterized, at the systemic level, by the development of low-grade inflammation, which has been identified as determining sarcopenia by blunting postprandial muscle anabolism. The causes of this "inflammageing" is still not clearly defined. An increased intestinal permeability, a microbiota dysbiosis and subsequent generation of intestinal then generalized inflammation have been hypothesized. The objective of this study was to test in vivo during aging if (1) a chronic low-grade intestinal inflammation can lead to anabolic resistance and muscle loss and (2) if a bacterial strain presenting anti-inflammatory properties could prevent these adverse effects. Methods: Young adult (6 m) and elderly rats (18 m) received Dextran Sodium Sulfate (DSS) for 28 days to generate low-grade intestinal inflammation, and received (PB1 or PB2 groups) or not (DSS group) one of the two S. Thermophilus strains (5 × 109 CFU/day) previously shown to present an anti-inflammatory potential in vitro. They were compared to pair fed control (PF). Muscle and colon weights and protein synthesis (using 13C Valine) were measured at slaughter. Muscle proteolysis, gut permeability and inflammatory markers were assessed only in old animals by RT-PCR or proteins quantifications (ELISA). Results: In both adult and old rats, DSS reduced absolute protein synthesis (ASR) in gastrocnemius muscle [-12.4% (PB1) and -9.5% (PB2) vs. PF, P < 0.05] and increased ASR in colon (+86% and +30.5%, respectively vs. PF, P < 0.05). PB1 (CNRZ160 strain) but not PB2 resulted in a higher muscle ASR as compared to DSS in adults (+18%, P < 0.05), a trend also observed for PB1 in old animals (+12%, P = 0.10). This was associated with a blunted increase in colon ASR. In old rats, PB1 also significantly decreased expression of markers of autophagy and ubiquitin-proteasome pathways vs. DSS groups and improved gut permeability (assessed by Occludin, Zonula Occludens 1 and Claudin 1 expression, P < 0.05) and alleviated systemic inflammation (A2M: -48% vs. DSS, P < 0.05). Conclusion: The loss of muscle anabolism associated with low-grade intestinal inflammation can be prevented by supplementation with anti-inflammatory CNRZ160 strain. We propose that the moderated gut inflammation by CNRZ160 may result in curtailed amino acids (AA) utilization by the gut, and subsequent restored AA systemic availability to support muscle protein accretion. Therefore, CNRZ160 could be considered as an efficient probiotic to modulate muscle mass loss and limit sarcopenia during aging.

Nutritional issues and dietary levers during gradual meat reduction - A sequential diet optimization study to achieve progressively healthier diets.

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.

Nutritionally adequate and environmentally respectful diets are possible for different diet groups: an optimized study from the NutriNet-Santé cohort.

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-Santé 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.This trial was registered at clinicaltrials.gov as NCT03335644.

Short-Term Supplementation of Sodium Nitrate vs. Sodium Chloride Increases Homoarginine Synthesis in Young Men Independent of Exercise.

The aim of the study was to investigate the effects of short-term oral administration of inorganic nitrate (NaNO3; n = 8) or placebo (NaCl; n = 9) (each 0.1 mmol/kg body weight/d for 9 days) on plasma amino acids, creatinine, and oxidative stress in healthy young men. At baseline, the plasma concentrations of amino acids did not differ between the groups. At the end of the study, the plasma concentrations of homoarginine (hArg; by 24%, p = 0.0001), citrulline and ornithine (Cit/Orn; by 16%, p = 0.015), and glutamine/glutamate (Gln/Glu; by 6%, p = 0.0003) were higher in the NaNO3 group compared to the NaCl group. The plasma concentrations of sarcosine (Sarc; by 28%, p < 0.0001), tyrosine (by 14%, p = 0.0051), phenylalanine (by 8%, p = 0.0026), and tryptophan (by 8%, p = 0.0047) were lower in the NaNO3 group compared to the NaCl group. These results suggest that nitrate administration affects amino-acid metabolism. The arginine/glycine amidinotransferase (AGAT) catalyzes two reactions: (1) the formation of l-homoarginine (hArg) and l-ornithine (Orn) from l-arginine (Arg) and l-lysine (Lys): Arg + Lys <−> hArg + Orn, with equilibrium constant Kharg; (2) the formation of guanidinoacetate (GAA) and Orn from Arg and glycine (Gly): Arg + Gly <−> GAA + Orn, with equilibrium constant Kgaa. The plasma Kgaa/KhArg ratio was lower in the NaNO3 group compared to the NaCl group (1.57 vs. 2.02, p = 0.0034). Our study suggests that supplementation of inorganic nitrate increases the AGAT-catalyzed synthesis of hArg and decreases the N-methyltransferase-catalyzed synthesis of GAA, the precursor of creatine. To our knowledge, this is the first study to demonstrate elevation of hArg synthesis by inorganic nitrate supplementation. Remarkably, an increase of 24% corresponds to the synthesis capacity of one kidney in healthy humans. Differences in the association between plasma concentrations of amino acids in the NaNO3 and NaCl groups suggest changes in amino-acid homeostasis. Plasma concentrations of the oxidative stress marker malondialdehyde (MDA) did not change after supplementation of NaNO3 or NaCl over the whole exercise time range. Plasma nitrite concentration turned out to be a more discriminant marker of NaNO3 ingestion than plasma nitrate (area under the receiver operating characteristic curve: 0.951 vs. 0.866, p < 0.0001 each).