The bioavailability of iron, zinc, protein and vitamin A is highly variable in French individual diets: Impact on nutrient inadequacy assessment and relation with the animal-to-plant ratio of diets

Adherence to an antioxidant diet and lifestyle is associated with reduced risk of cardiovascular disease and mortality among adults with nonalcoholic fatty liver disease: evidence from NHANES 1999-2018

Background

Nonalcoholic fatty liver disease (NAFLD) stands a prevalent chronic liver condition significantly influenced by oxidative stress. We investigated the unclear relationship between antioxidant-rich diet and lifestyle and cardiovascular disease (CVD) prevalence rate and mortality in adult patients with NAFLD.

Methods

This study utilized data from the National Health and Nutrition Examination Survey (NHAENS) spanning from 1999 to 2018 to investigate the association between adherence to an antioxidant-rich diet and lifestyle and the cardiovascular disease (CVD) prevalence rate and mortality in adult patients with NAFLD. The study employed the Oxidative Balance Score (OBS) to define antioxidant diet and lifestyle.

Results

Including 8,670 adult patients with NAFLD, the study revealed an inverse association between OBS and the prevalence of most CVD conditions. Fully adjusted models demonstrated that each unit increase in diet OBS, lifestyle OBS, and overall OBS corresponded to a 2, 7, and 2% reduction in all-cause mortality, respectively. In models 2, findings revealed that lifestyle Q2 and Q3 were linked to reduced cancer mortality, whereas diet and overall OBS did not exhibit an association. Additionally, Stratified analysis revealed that age (<45 years) and education level (> high school) significantly influenced the association between the OBS and the prevalence of CVD.

Conclusion

These results underscore the protective link between adherence to an antioxidant diet and lifestyle and a diminished prevalence of CVD and mortality in adults with NAFLD, particularly among younger and higher-educated populations.

Exploring tradeoffs among diet quality and environmental impacts in self-selected diets: a population-based study

PURPOSE

Proposed sustainable diets often deviate dramatically from currently consumed diets, excluding or drastically reducing entire food groups. Moreover, their environmental sustainability tends to be measured only in terms of greenhouse gases emissions. The aim of this study was to overcome these limitations and identify a cluster of already adopted, relatively healthy diets with substantially lower environmental impacts than the average diet. We also aimed to estimate the reduction in multiple environmental impacts that could be achieved by shifting to this diet cluster and highlight possible tradeoffs among environmental impacts.

METHODS

The diet clusters were identified by applying energy-adjusted multiple factor analysis and hierarchical clustering to the dietary data of the National FinHealth 2017 Study (n = 5125) harmonized with life cycle assessment data on food products from Agribalyse 3.0 and Agri-Footprint using nutrient intakes and global warming potential, land use, and eutrophication of marine and freshwater systems as the active variables.

RESULTS

We identified five diet clusters, none of which had the highest overall diet quality and lowest impact for all four environmental indicators. One cluster, including twenty percent of the individuals in the sample was identified as a "best compromise" diet with the highest diet quality and the second lowest environmental impacts of all clusters, except for freshwater eutrophication. The cluster did not exclude any food groups, but included more fruits, vegetables, and fish and less of all other animal-source foods than average. Shifting to this cluster diet could raise diet quality while achieving significant reductions in most but not all environmental impacts.

CONCLUSION

There are tradeoffs among the environmental impacts of diets. Thus, future dietary analyses should consider multiple sustainability indicators simultaneously. Cluster analysis is a useful tool to help design tailored, socio-culturally acceptable dietary transition paths towards high diet quality and lower environmental impact.

Estimation of the availability of iron in the school meals of Municipal Centers for Early Childhood Education of a capital city in northeastern Brazil

The final stage of Fe deficiency is Fe deficiency anaemia, with repercussions for human health, especially in children under 5 years of age. Studies conducted in Brazilian public daycare centres show high prevalence of anaemia. The present study aims to evaluate the availability of Fe in the meals of the Municipal Centers of Early Childhood Education in Maceió. The experimental design comprises selection of algorithms, menu evaluation, calculation of the estimates, comparison between the estimates obtained and the recommendations, and analysis of correlation between meal constituents, and of the concordance between the absorbable Fe estimates. Four algorithms were selected and a monthly menu consisting of 22 d. The correlation analysis showed a moderate positive correlation to animal tissue (AT) v. non-heme iron (r = 0·42; P = 0·04), and negative to AT v. Ca (r = -0·54; P = 0·09) and Ca v. phytates (r = -0·46, P = 0·03). Estimates of absorbable Fe ranged from 0·23 to 0·44 mg/d. The amount of Fe available, unlike the total amount of Fe offered, does not meet the nutritional recommendations on most school days. The Bland-Altman analysis indicated that the Monsen and Balinfty and Rickard et al. showed greater agreement. The results confirm the need to adopt strategies to increase the availability of Fe in school meals.

Association between Dietary Total Antioxidant Capacity of Antioxidant Vitamins and the Risk of Stroke among US Adults

The intake of antioxidant vitamins can scavenge free radicals and reduce oxidative stress, which may be beneficial for stroke. However, the relationship between total antioxidant capacity (TAC) of antioxidant vitamins and stroke is controversial. This study aims to investigate the association between dietary TAC and the risk of stroke in US adults. This study included participants over 20 years old from the 2001-2018 National Health and Nutrition Examination Survey (NHANES). Data from two 24 h dietary recalls were used to estimate the usual intake of antioxidant vitamins. TAC was calculated by the vitamin C equivalent antioxidant capacity reference values of individual antioxidant vitamins. Survey-weighted generalized linear models were performed to evaluate the relationship between TAC and the risk of stroke. A restricted cubic spline regression model was used to investigate the dose-response association. A total of 37,045 participants was involved, of whom 1391 suffered a stroke. Compared with the first tertile, the participants in the second tertile of TAC showed a lower risk of stroke (OR = 0.788, 95% CI: 0.662, 0.936) after adjusting for potential risk factors. The dose-response analysis showed a gradual increase in the risk of stroke as TAC decreases. Subgroups analyses indicated that this association was primarily in the population of those aged over 60 years old, who were female, consumed alcohol, were a former smoker and inactive. The sensitivity analysis presented consistent results. These results suggest that deficiency of dietary TAC was associated with an increased risk of stroke, particularly in populations with underlying oxidative stress injury.

Nutritional quality and greenhouse gas emissions of vegetarian and non-vegetarian primary school meals: A case study in Dijon, France

Since 2018 in France, national regulation mandates that school canteens serve a weekly vegetarian meal to reduce school canteens' environmental impact in addition to previous regulations imposing nutritional composition guidelines. However, a lunch without meat is often perceived as inadequate to cover the nutritional needs of children. The present study aims to assess the nutritional quality and greenhouse gas emissions (GHGE) of vegetarian and non-vegetarian school meals served in primary schools in Dijon, France. The catering department provided the composition of 249 meals served in 2019. Nutritional content and GHGE were retrieved from national food databases. The portion size of each meal component was the standard portion size recommended by the relevant French authority (GEMRCN). Meals were classified into vegetarian meals, i.e., without meat or fish (n = 66), or non-vegetarian meals (n = 183). The nutritional adequacy of the meals for children aged from 6 to 11 years was estimated using the mean adequacy ratio (MAR/2,000 kcal) as the mean percentage of daily recommended intake for 23 nutrients and the mean excess ratio (MER/2,000 kcal) as the mean percentage of excess compared to the maximum daily recommended value for three nutrients. This analysis of actual school meals shows that both vegetarian and non-vegetarian meals had a similar good nutritional quality with MAR/2,000 kcal of 87.5% (SD 5.8) for vegetarian and of 88.5% (SD 4.5) for non-vegetarian meals, and a MER/2,000 kcal of 19.3% (SD 15.0) for vegetarian and of 19.1% (SD 18.6) for non-vegetarian meals. GHGE were more than twofold reduced in vegetarian compared to non-vegetarian meals (0.9 (SD 0.3) vs. 2.1 (SD 1.0) kgC0₂ eq/meal). Thus, increasing the frequency of vegetarian meals, by serving egg-based, dairy-based or vegan recipes more frequently, would reduce GHGE while maintaining adequate nutritional quality of primary school meals.

Number of meal components, nutritional guidelines, vegetarian meals, avoiding ruminant meat: what is the best trade-off for improving school meal sustainability?

PURPOSE

School meals have the potential to promote more sustainable diets. Our aim was to identify the best trade-off between nutrition and the environment by applying four levers to school meals: (i) reducing the number of meal components, (ii) complying with the French school nutritional guidelines, (iii) increasing the number of vegetarian meals, and/or (iv) avoiding ruminant meat.

METHODS

Levers were analyzed alone or in combination in 17 scenarios. For each scenario, 100 series of 20 meals were generated from a database of 2316 school dishes using mathematical optimization. The nutritional quality of the series was assessed through the mean adequacy ratio (MAR/2000 kcal). Seven environmental impacts were considered such as greenhouse gas emissions (GHGE). One scenario, close to series usually served in French schools (containing four vegetarian meals, at least four ruminant meat-based meals, and at least four fish-based meals) was considered as the reference scenario.

RESULTS

Reducing the number of meal components induced an important decrease of the energy content but the environmental impact was little altered. Complying with school-specific nutritional guidelines ensured nutritional quality but slightly increased GHGE. Increasing the number of vegetarian meals decreased GHGE (from 11.7 to 61.2%) but decreased nutritional quality, especially when all meals were vegetarian (MAR = 88.1% against 95.3% in the reference scenario). Compared to the reference scenario, series with 12 vegetarian meals, 4 meals containing fish and 4 meals containing pork or poultry reduced GHGE by 50% while maintaining good nutritional quality (MAR = 94.0%).

CONCLUSION

Updating French school nutritional guidelines by increasing the number of vegetarian meals up to 12 over 20 and serving non-ruminant meats and fish with the other meals would be the best trade-off for decreasing the environmental impacts of meals without altering their nutritional quality.

The role of holistic nutritional properties of diets in the assessment of food system and dietary sustainability

Advancing sustainable diets for nutrition security and sustainable development necessitates clear nutrition metrics for measuring nutritional quality of diets. Food composition, nutrient requirements, and dietary intake are among the most common nutrition metrics used in the current assessment of sustainable diets. Broadly, most studies in the area classify animal-source foods (ASF) as having a substantially higher environmental footprint in comparison to plant-source foods (PSF). As a result, much of the current dietary advice promulgates diets containing higher proportions of PSF. However, this generalization is misleading since most of these studies do not distinguish between the gross and bioavailable nutrient fractions in mixed human diets. The bioavailability of essential nutrients including β-carotene, vitamin B-12, iron, zinc, calcium, and indispensable amino acids varies greatly across different diets. The failure to consider bioavailability in sustainability measurements undermines the complementary role that ASF play in achieving nutrition security in vulnerable populations. This article critically reviews the scientific evidence on the holistic nutritional quality of diets and identifies methodological problems that exist in the way the nutritional quality of diets is measured. Finally, we discuss the importance of developing nutrient bioavailability as a requisite nutrition metric to contextualize the environmental impacts of different diets.

Integrating the soybean-maize-chicken value chains to attain nutritious diets in Tanzania

In Tanzania, diets are dominated by starchy staple crops such as maize, levels of malnutrition are high and largely attributed to lack of dietary diversity. We employed fuzzy cognitive mapping to understand the current soybean, maize and chicken value chains, to highlight stakeholder relationships and to identify entry points for value chain integration to support nutritious diets in Tanzania. The fuzzy cognitive maps were constructed based on information gathered during household interviews with 569 farming households, followed by a participatory workshop with 54 stakeholders involved in the three value chains. We found that the soybean, maize and chicken value chains were interconnected, particularly at the level of the smallholder farming systems and at processing facilities. Smallholder farming households were part of one or more value chains. Chicken feed is an important entry point for integrating the three value chains, as maize and soybean meal are the main sources of energy and protein for chicken. Unlike maize, the utilization of soybean in chicken feed is limited, mainly due to inadequate quality of processing of soybean grain into meal. As a result, the soybean grain produced by smallholders is mainly exported to neighbouring countries for further processing, and soybean meal is imported at relatively high prices. Enhancing local sourcing and adequate processing of soybean, coupled with strengthening the integration of smallholder farmers with other soybean, maize and chicken value chain actors offers an important opportunity to improve access to nutritious diets for local people. Our method revealed the importance of interlinkages that integrate the value chains into a network within domestic markets.

Pulses Twice a Week in Replacement of Meat Modestly Increases Diet Sustainability

The French food-based dietary guidelines recommend eating pulses at least twice a week and to reduce meat consumption. This study assessed the impact on the sustainability characteristics (nutrition, cost, environment) of individual diets of meeting the pulse guideline. Dietary data of 2028 adults from the Esteban survey were completed with the nutritional content (considering bioavailability on iron, zinc and protein), price and environmental impacts of foods. When the pulse guideline (i.e., 57 g/day) was not met, two substitution scenarios raised the quantity of pulses to the recommended level, in replacement of an equivalent portion of (i) starches or (ii) meat. Only 9.6% of the participants reached the pulse guideline. Diet sustainability characteristics improved with the meat scenario (nutritional indicators improved; diet cost, greenhouse gas emissions and acidification decreased), while several indicators deteriorated with the starches scenario. Zinc available for absorption slightly decreased in both scenarios while iron available for absorption decreased in the meat scenario only. Increasing pulse consumption to two portions/week could modestly improve the sustainability of diets when pulses replace meat but not starches. Cultural acceptability of that substitution still needs to be proven, and iron and zinc status of individuals at risk of deficiency should be monitored.

Nutritional composition and cost of home-prepared enteral tube feeding

BACKGROUND & AIMS

To aid in dietary prescription and contribute to the promotion of food and nutritional safety of individuals, this study's objective was to compare the nutritional composition and cost of homemade preparations, blended preparations, and commercial enteral formula prescribed for adults and elderly people at hospital discharge.

METHODS

All hospitals in a Brazilian city that prescribed the three types of enteral formulations provide information about enteral formulations prescribed for home use. Enteral formulations were estimated in relation to energy content, macronutrients, micronutrients, and cost.

RESULTS

Homemade diets, blended and commercial enteral formulations showed, on average, normoproteic, normoglicidic and normolipidic features, with average daily costs (US$/2000 kcal) of US$ 29.77, 50.56 and 154.44, respectively. The cost was higher in the commercial enteral formulas (P < .001); vitamin and mineral content were poorer in homemade preparations.

CONCLUSIONS

The homemade and blended enteral preparations cost less, but were generally lower in micronutrients, calling for more adequate dietary prescription.

Vitamin A levels are decreased but not influenced by glucose- or lipid-lowering medications in subjects with type 2 diabetes

Background and aim

Type 2 diabetes (T2D) is a complex polygenic disease with unclear mechanisms. Clinical studies on the association of vitamin A with T2D in humans are still controversial. Herein, we aimed to investigate the plasma levels of vitamin A, predictor factors, and its correlations with clinical phenotypes in Emirati population. The effect of glucose-and lipid-lowering medications on vitamin A levels was also studied.

Methods

A cross-sectional cohort comprised 158 T2D-subjects and 90 healthy controls were recruited from the United Arab Emirates National Diabetes Study (UAEDIAB). All anthropometric, clinical, and biomedical measurements were collected. Plasma levels of vitamin A were determined using ELISA assay.

Results

Levels of vitamin A were significantly lower in T2D-subjects compared to healthy control (p < 0.01). Vitamin A levels were unaffected by gender base and inversely correlated with age, fasting blood glucose (FBG), glycated hemoglobin (HbA1c), waist circumference, triglycerides, and body mass index (BMI). Regression analysis revealed that HbA1c and age are predictors for vitamin A. Intake of glucose- or lipid-lowering medications showed no effect on vitamin A levels.

Conclusion

HbA1c and age are predictors for low levels of vitamin A among Emirati-T2D subjects. No influence of glucose and lipid-lowering medications on the plasma levels of vitamin A.

A "Fork-to-Farm" Multi-Scale Approach to Promote Sustainable Food Systems for Nutrition and Health: A Perspective for the Mediterranean Region

Mediterranean countries are undergoing dietary and nutritional changes that affect their inhabitants' health, while facing massive environmental challenges. The increasing demand of water in agriculture, the capacity to maintain local food production, and the growing dependence on food imports are interconnected issues that must be addressed to ensure food security and nutrition in the Mediterranean region. Here, we present the conceptual framework and methodologies developed by the MEDINA-Study Group for rethinking food systems toward sustainable consumption and production modes. Based on its multidisciplinary expertise, the MEDINA-Study Group designed a "fork-to-farm" multi-scale approach, stemming from current dietary habits and examining how some options to nutritionally improve these habits might affect the food systems. This approach was developed for research activities in the South of France and Tunisia, two areas with very different diet-agriculture-environment nexus. The conceptual framework is based on the analysis of elements of the food systems (from consumption to production) at different levels (individual, household, regional and national levels). The methods include: (i) modeling options of dietary changes at different scales, in order to nutritionally optimize food consumption-production without increasing the environmental impact, (ii) translating the best-choice changes into possible policy actions, (iii) testing the acceptability and feasibility of these actions with several stakeholders, and (iv) producing guidelines for sustainable food choices and production. The MEDINA-Study Group identified additional issues that could be included in a future framework to help designing ambitious agricultural, food and health policies in the Mediterranean region.

Dietary Iron Bioavailability: Agreement between Estimation Methods and Association with Serum Ferritin Concentrations in Women of Childbearing Age

Predictive iron bioavailability (FeBio) methods aimed at evaluating the association between diet and body iron have been proposed, but few studies explored their validity and practical usefulness in epidemiological studies. In this cross-sectional study involving 127 women (18–42 years) with presumably steady-state body iron balance, correlations were checked among various FeBio estimates (probabilistic approach and meal-based and diet-based algorithms) and serum ferritin (SF) concentrations. Iron deficiency was defined as SF < 15 µg/L. Pearson correlation, Friedman test, and linear regression were employed. Iron intake and prevalence of iron deficiency were 10.9 mg/day and 12.6%. Algorithm estimates were strongly correlated (0.69≤ r ≥0.85; p < 0.001), although diet-based models (8.5–8.9%) diverged from meal-based models (11.6–12.8%; p < 0.001). Still, all algorithms underestimated the probabilistic approach (17.2%). No significant association was found between SF and FeBio from Monsen (1978), Reddy (2000), and Armah (2013) algorithms. Nevertheless, there was a 30–37% difference in SF concentrations between women stratified at extreme tertiles of FeBio from Hallberg and Hulthén (2000) and Collings’ (2013) models. The results demonstrate discordance of FeBio from probabilistic approach and algorithm methods while suggesting two models with best performances to rank individuals according to their bioavailable iron intakes.

Effect of low energy diet for eight weeks to adults with overweight or obesity on folate, retinol, vitamin B12, D and E status and the degree of inflammation: a post hoc analysis of a randomized intervention trial

Background

Obesity is associated with vitamin insufficiency and low grade inflammation. The purpose of this study was to investigate the effect of weight loss on folate, retinol, vitamin B₁₂, D and E status and the degree of inflammation.

Methods

Out of 110, 85 individuals (75% women) aged 39 ± 11 years with a mean ± SD BMI of 33 ± 4 kg/m², completed an eight-week low energy diet (LED). Serum concentration of folate, retinol, B₁₂, D and E and C-reactive protein and homocysteine (Hcy) were measured at baseline and at end of the LED.

Results

At baseline, 8% of the participants were deficient in folate, 13% in vitamin B₁₂, 2% in retinol, 28% in vitamin D (72% were insufficient in vitamin D), and none were deficient in vitamin E. At baseline, BMI was inversely associated with retinol (P < 0.05) as was total and abdominal fat percentage with folate (P < 0.05); further BMI and measures of adiposity were positively associated with CRP (P < 0.01) and Hcy (P < 0.05). Homocysteine was inversely associated with all vitamins but retinol (P < 0.001). After the LED, the participants lost a mean [95% confidence intervals] of 12.3 [− 13.1,-11.6] kg. The serum concentration of folate, vitamin B₁₂ and D were increased (P < 0.001) after the LED whereas the concentration of retinol and vitamin E were reduced (P < 0.001).

Conclusion

Eight-weeks LED resulted in 13% weight loss and an increase in the serum concentrations of folate, vitamin B₁₂ and D. Baseline adiposity was inversely associated with folate and retinol, and positively associated with markers of inflammation.

Trial registration

Ethical Committee of Copenhagen as no. H-4-2013-135, NCT01561131.

The opportunity cost of animal based diets exceeds all food losses

With a third of all food production lost via leaky supply chains or spoilage, food loss is a key contributor to global food insecurity. Demand for resource-intensive animal-based food further limits food availability. In this paper, we show that plant-based replacements for each of the major animal categories in the United States (beef, pork, dairy, poultry, and eggs) can produce twofold to 20-fold more nutritionally similar food per unit cropland. Replacing all animal-based items with plant-based replacement diets can add enough food to feed 350 million additional people, more than the expected benefits of eliminating all supply chain food loss.

Food loss is widely recognized as undermining food security and environmental sustainability. However, consumption of resource-intensive food items instead of more efficient, equally nutritious alternatives can also be considered as an effective food loss. Here we define and quantify these opportunity food losses as the food loss associated with consuming resource-intensive animal-based items instead of plant-based alternatives which are nutritionally comparable, e.g., in terms of protein content. We consider replacements that minimize cropland use for each of the main US animal-based food categories. We find that although the characteristic conventional retail-to-consumer food losses are ≈30% for plant and animal products, the opportunity food losses of beef, pork, dairy, poultry, and eggs are 96%, 90%, 75%, 50%, and 40%, respectively. This arises because plant-based replacement diets can produce 20-fold and twofold more nutritionally similar food per cropland than beef and eggs, the most and least resource-intensive animal categories, respectively. Although conventional and opportunity food losses are both targets for improvement, the high opportunity food losses highlight the large potential savings beyond conventionally defined food losses. Concurrently replacing all animal-based items in the US diet with plant-based alternatives will add enough food to feed, in full, 350 million additional people, well above the expected benefits of eliminating all supply chain food waste. These results highlight the importance of dietary shifts to improving food availability and security.

A review on potential roles of vitamins in incidence, progression, and improvement of multiple sclerosis

Multiple Sclerosis (MS) is an inflammatory and neurodegenerative disease, with unknown etiology. Vitamins, as important micronutrients playing different roles in body, seem to be important in MS pathogenesis. In vitro, in vivo and human studies, supports the protective role of some vitamins in MS occurrence or progression. Current study reviews recent insights and reports about the importance of vitamins in MS incidence or progression. In accordance, the importance of all water and fat-soluble vitamins in MS pathogenesis based on observational studies in human population and their role in the function of immune system as well as possible therapeutic opportunities are discussed in depth throughout this review.

Patterns of Protein Food Intake Are Associated with Nutrient Adequacy in the General French Adult Population

Protein food intake appears to partially structure dietary patterns, as most current emergent diets (e.g., vegetarian and flexitarian) can be described according to their levels of specific protein sources. However, few data are available on dietary protein patterns in the general population and their association with nutrient adequacy. Based on protein food intake data concerning 1678 adults from a representative French national dietary survey, and non-negative-matrix factorization followed by cluster analysis, we were able to identify distinctive dietary protein patterns and compare their nutrient adequacy (using PANDiet probabilistic scoring). The findings revealed eight patterns that clearly discriminate protein intakes and were characterized by the intakes of one or more specific protein foods: ‘Processed meat’, ‘Poultry’, ‘Pork’, ‘Traditional’, ‘Milk’, ‘Take-away’, ‘Beef’ and ‘Fish’. ‘Fish eaters’ and ‘Milk drinkers’ had the highest overall nutrient adequacy, whereas that of ‘Pork’ and ‘Take-away eaters’ was the lowest. Nutrient adequacy could often be accounted for by the characteristics of the food contributing to protein intake: ‘Meat eaters’ had high probability of adequacy for iron and zinc, for example. We concluded that protein patterns constitute strong elements in the background structure of the dietary intake and are associated with the nutrient profile that they convey.

Integrating nutrient bioavailability and co-production links when identifying sustainable diets: How low should we reduce meat consumption?

Background

Reducing the consumption of meat and other animal-based products is widely advocated to improve the sustainability of diets in high-income countries. However, such reduction may impair nutritional adequacy, since the bioavailability of key nutrients is higher when they come from animal- vs plant-based foods. Meat reduction may also affect the balance between foods co-produced within the same animal production system.

Objective

The objective was to assess the impact of introducing nutrient bioavailability and co-production links considerations on the dietary changes needed − especially regarding meat ‒ to improve diet sustainability.

Methods

Diet optimization with linear and non-linear programming was used to design, for each gender, three modeled diets departing the least from the mean observed French diet (OBS) while reducing by at least 30% the diet-related environmental impacts (greenhouse gas emissions, eutrophication, acidification): i) in the nutrition-environment (NE) model, the fulfillment of recommended dietary allowances for all nutrients was imposed; ii) in the NE-bioavailability (NEB) model, nutritional adequacy was further ensured by accounting for iron, zinc, protein and provitamin A bioavailability; iii) in the NEB-co-production (NEB-CP) model, two links between co-produced animal foods (milk–beef and blood sausage–pork) were additionally included into the models by proportionally co-constraining their respective quantities. The price and environmental impacts of individual foods were assumed to be constant.

Results

‘Fruit and vegetables’ and ‘Starches’ quantities increased in all modeled diets compared to OBS. In parallel, total meat and ruminant meat quantities decreased. Starting from 110g/d women’s OBS diet (168g/d for men), total meat quantity decreased by 78%, 67% and 32% for women (68%, 66% and 62% for men) in NE, NEB and NEB-CP diets, respectively. Starting from 36g/d women’s OBS diet (54g/d for men), ruminant meat quantity dropped severely by 84% and 87% in NE and NEB diets for women (80% and 78% for men), whereas it only decreased by 27% in NEB-CP diets (38% for men). The share of energy and proteins of animal origin was similar for the 3 modeled diets (approximately 1/5 of total energy, and 1/2 of protein) and lower than in OBS diet (approximately 1/3 of total energy, and 2/3 of protein).

Conclusions

Decreasing meat content was strictly needed to achieve more sustainable diets for French adults, but the reduction was less severe when nutrient bioavailability and co-production links were taken into account.

Nutritional Quality of School Meals in France: Impact of Guidelines and the Role of Protein Dishes

In France, school meals must comply with 15 frequency criteria (FC) expressed as nutritional requirements (e.g., “starters containing more than 15% fat served no more than four times out of 20”) in a series of 20 consecutive meals. The objective was to assess, for the first time, the nutritional impact of complying with French school food FC. Based on 40 series of meals actually served in primary schools (“observed series”), several scenarios (1600 series per scenario) of compliance or non-compliance with FC were simulated, and nutritional quality was assessed via the mean adequacy ratio (MAR/2000 kcal). In the observed series, only 9.7 FC on average (range 4–14) were fulfilled. In the simulated series: (i) MAR was positively associated with FC compliance level, with the highest MAR obtained with complete compliance; (ii) MAR decreased when meat or fish-based dishes were replaced by dishes without meat or fish; and (iii) removing the protein dish without replacement led to the lowest MAR. This study demonstrates that French school food guidelines ensure good nutritional quality of food services. It also shows that generalizing the service of meals without meat or fish would deteriorate overall nutritional quality, highlighting the need to define the composition of vegetarian dishes and their frequency of service to children.

Protein Adequacy Is Primarily a Matter of Protein Quantity, Not Quality: Modeling an Increase in Plant:Animal Protein Ratio in French Adults

A downward trend in animal protein (AP) intake has been observed in western countries over the last decade and the effects of such a transition on protein adequacy remain debatable. Using the probability approach and diet modeling with data on 1678 adults from a representative French national dietary survey, we studied the sensitivity of the adequacy of protein and amino acid intakes to changes in animal:plant protein. We simulated the gradual substitution of AP with different mixtures of plant protein (PP), containing various proportions of PP already consumed and legumes, nuts and seeds (LNS). We found that protein and amino acid intakes met dietary requirements in virtually the entire population studied. Up to 50% of PP in diets, protein and amino acid intakes were adequate in all models. From 50%, protein inadequacy was primary due to protein quantity, and from 70%, to protein quality (as lysine inadequacy). The introduction of LNS in the mixture substituting AP led to adequate protein intakes for higher percentages of PP. An increase in PP based on the current pattern of plant protein sources, low in protein:energy, could lead to inadequate protein intake, but the contribution of LNS ensures the safety of a further transition.

Nutritional and greenhouse gas impacts of removing animals from US agriculture

As a major contributor to agricultural greenhouse gas (GHG) emissions, it has been suggested that reducing animal agriculture or consumption of animal-derived foods may reduce GHGs and enhance food security. Because the total removal of animals provides the extreme boundary to potential mitigation options and requires the fewest assumptions to model, the yearly nutritional and GHG impacts of eliminating animals from US agriculture were quantified. Animal-derived foods currently provide energy (24% of total), protein (48%), essential fatty acids (23-100%), and essential amino acids (34-67%) available for human consumption in the United States. The US livestock industry employs 1.6 × 106 people and accounts for $31.8 billion in exports. Livestock recycle more than 43.2 × 109 kg of human-inedible food and fiber processing byproducts, converting them into human-edible food, pet food, industrial products, and 4 × 109 kg of N fertilizer. Although modeled plants-only agriculture produced 23% more food, it met fewer of the US population's requirements for essential nutrients. When nutritional adequacy was evaluated by using least-cost diets produced from foods available, more nutrient deficiencies, a greater excess of energy, and a need to consume a greater amount of food solids were encountered in plants-only diets. In the simulated system with no animals, estimated agricultural GHG decreased (28%), but did not fully counterbalance the animal contribution of GHG (49% in this model). This assessment suggests that removing animals from US agriculture would reduce agricultural GHG emissions, but would also create a food supply incapable of supporting the US population's nutritional requirements.