Plant-Protein Diversity Is Critical to Ensuring the Nutritional Adequacy of Diets When Replacing Animal With Plant Protein: Observed and Modeled Diets of French Adults (INCA3)

Legumes and common beans in sustainable diets: nutritional quality, environmental benefits, spread and use in food preparations

In recent decades, scarcity of available resources, population growth and the widening in the consumption of processed foods and of animal origin have made the current food system unsustainable. High-income countries have shifted towards food consumption patterns which is causing an increasingly process of environmental degradation and depletion of natural resources, with the increased incidence of malnutrition due to excess (obesity and non-communicable disease) and due to chronic food deprivation. An urgent challenge is, therefore, to move towards more healthy and sustainable eating choices and reorientating food production and distribution to obtain a human and planetary health benefit. In this regard, legumes represent a less expensive source of nutrients for low-income countries, and a sustainable healthier option than animal-based proteins in developed countries. Although legumes are the basis of many traditional dishes worldwide, and in recent years they have also been used in the formulation of new food products, their consumption is still scarce. Common beans, which are among the most consumed pulses worldwide, have been the focus of many studies to boost their nutritional properties, to find strategies to facilitate cultivation under biotic/abiotic stress, to increase yield, reduce antinutrients contents and rise the micronutrient level. The versatility of beans could be the key for the increase of their consumption, as it allows to include them in a vast range of food preparations, to create new formulations and to reinvent traditional legume-based recipes with optimal nutritional healthy characteristics.

True Ileal Amino Acid Digestibility and Protein Quality of 15N-Labeled Faba Bean in Healthy Humans

BACKGROUND

The recommended transition toward more plant-based diets, particularly containing legumes, requires a wider knowledge of plant protein bioavailability. Faba beans are cultivated at different latitudes and are used increasingly in human nutrition.

OBJECTIVES

We aimed to assess the nutritional quality of faba bean protein in healthy volunteers equipped with an intestinal tube to implement the ileal 15N balance method.

METHODS

Nine volunteers completed the study (7 males, 2 females, aged 33 ± 10 y, BMI: 24.7 ± 2.6 kg/m2). They were equipped with a nasoileal tube. After fasting overnight, they ingested a test meal consisting of cooked mash of dehulled faba bean seeds (20 g protein per serving of approximately 250 g) intrinsically labeled with 15N. Samples of ileal contents, plasma, and urine were collected over an 8-h postprandial period. Undigested nitrogen (N) and amino acids (AAs) were determined using isotopic MS, and subsequently, ileal digestibility and digestible indispensable amino acid score (DIAAS) were calculated. The measurement of postprandial deamination allowed calculation of the net postprandial protein utilization (NPPU).

RESULTS

The ileal N digestibility was 84.1% ± 7.7%. Postprandial deamination represented 19.2% ± 3.6% of ingested N, and the NPPU was 64.7% ± 9.7%. The ileal digestibility of individual AAs varied from 85.1% ± 13.7% for histidine to 94.2% ± 3.6% for glutamine + glutamate. The mean AA digestibility was ∼6 percentage points higher than the digestibility of N, reaching 89.8% ± 5.9%, whereas indispensable AA digestibility was 88.0% ± 7.3%. Histidine and tryptophan were the first limiting AAs [DIAAS = 0.77 (calculated by legume-specific N-to-protein conversion factor 5.4); 0.67 (by default factor 6.25)]. Sulfur AAs were limiting to a lesser extent [DIAA ratio = 0.94 (N × 5.4); 0.81 (N × 6.25)].

CONCLUSIONS

Protein ileal digestibility of cooked, dehulled faba beans in humans was moderate (<85%), but that of AAs was close to 90%. Overall protein quality was restricted by the limited histidine and tryptophan content. This trial was registered at clinicaltrials.gov as NCT05047757.

Improving the nutrient quality of foods and beverages using product specific standards for positive nutrients and ingredients will help to increase mean population intakes toward dietary guidelines

Background

A shift toward more sustainable diets, rich in plant-based foods and with fewer animal-derived foods, is needed and will lead to improved health and environmental benefits. Food industry needs to play a part and broaden the scope of product reformulation beyond the reduction of nutrients to limit to increasing ingredients and nutrients in line with dietary recommendations for a healthy sustainable diet.

Methods

The Positive Nutrition Standards (PNS) were defined to increase the consumption of recommended ingredients and nutrients. The PNS were set by translating WHO and Codex guidance into product group standards, considering the role of the product group in the diet. The potential impact of the PNS for vegetables, wholegrain and fibre was modeled using data from the US NHANES 2017-2018 survey, assuming that, foods consumed would be reformulated to meet the standards where relevant.

Results

The modeling showed that application of the PNS could increase mean population intakes by 30% for fibre, by more than 50% for vegetables and even double the intake of wholegrain. However, reformulation alone would not be sufficient to reach recommended intake levels.

Conclusion

The PNS described in this paper can help to increase intakes of relevant positive nutrients and ingredients. However, a multistakeholder approach is needed to encourage consumers to make additionally required dietary shifts to meet the recommendations for positive nutrients and ingredients.

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.

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 thougt 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. Adv Nutr 2023;xx:xx-xx.

Partial replacement of red and processed meat with legumes: a modelling study of the impact on nutrient intakes and nutrient adequacy on the population level

OBJECTIVE

The shift towards plant-based diets with less meat and more legumes is a global target and requires an understanding of the consequences of dietary adequacy on the population level. Our aim was to model the impact of partial replacement of red and processed meat with legumes on nutrient intakes and population shares below dietary reference intakes.

DESIGN

Modelling study with three scenarios anchored in meat cut-offs: ≤ 70 g/d (Finnish dietary guideline); ≤ 50 g/d (Danish dietary guideline); ≤ 30 g/d (EAT-Lancet recommendation). In all subjects, the amount of meat in grams over the cut-off was replaced with the same amount of legumes. The SPADE method was used to model usual intake distributions. Meaningful differences in average intakes and in population shares below dietary reference intakes compared to the reference (FinDiet) were evaluated based on non-overlapping 95 % CI.

SETTING

Finnish national food consumption survey (FinDiet 2017).

SUBJECTS

Finnish adults (n 1655) aged18-74 years (47 % men).

RESULTS

The scenarios introduced increases in the average intakes of fibre, folate, K, Mg, Cu and Fe, and decreases in intakes of saturated fat, niacin, vitamin B12, Se and Zn. Meaningful shifts of the usual intake distributions of fibre and folate towards improvement in intakes emerged already in 'scenario 70 g'. Overall, distribution shifts towards a higher probability of inadequate intakes of the studied nutrients were not observed.

CONCLUSIONS

These results support the public health message to partly replace meat with legumes and may benefit nutrition policy actions towards sustainable diets in the Nordic countries and beyond.

Plant and Animal Protein Intakes Largely Explain the Nutritional Quality and Health Value of Diets Higher in Plants: A Path Analysis in French Adults

Diets higher in plants are associated with lower risks of chronic diseases. However, animal foods, which are rich in protein, are also rich in some important minerals and vitamins. Using data from a representative survey in France (INCA3, n = 1,125), we used path analyses as a mediation-like approach to decipher the importance of plant and animal proteins in the relationship between the plant-based diet index (PDI) and diet quality. We used three types of diet quality scores, namely, nutrient security, positive nutrient adequacy, and long-term mortality risk of four diet-related diseases (i.e., coronary heart disease, stroke, type 2 diabetes, and colorectal cancer). We identified positive and negative mediations, i.e., changes in plant/animal protein intake that are associated with changes in PDI, and favor or limit the association with the diet quality score. The PDI was positively associated with the risk of long-term mortality but not significantly with nutrient adequacy or nutrient security. A positive mediation by plant protein was found for all diet quality scores (specific indirect effects (SIEs) ranging from 0.04 to 0.10 SD). Conversely, the association between PDI and nutrient adequacy (but not nutrient security) was negatively mediated by animal protein intake (SIE: −0.06 SD). In further detailed models, the association between PDI and diet quality was mainly positively mediated by protein foods from the fruit-vegetables-legumes group (0.01 SD for the nutrient security and 0.02 SD for the nutrient adequacy) and whole grains (0.02 SD for the nutrient adequacy). Our data suggest that the positive impact of plant-based diets on diet quality is largely driven by higher intakes of plant protein foods, especially from fruits-vegetables-legumes and whole grains. Conversely, lower animal protein intake tends to limit the positive impact of plant-based diets on overall positive nutrient adequacy but not security. Protein sources appear critical to healthy plant-based diets.

Protein Quality Changes of Vegan Day Menus with Different Plant Protein Source Compositions

To underline the importance of protein quality in plant-based diets, we estimated the protein quality of different exclusively plant-protein-based day menus that are based on the "planetary health diet" developed by the EAT-Lancet Commission. PDCAAS and DIAAS were used to estimate the protein quality (PQ) and fulfilling of the amino acid recommendation for adults in vegan daily menus based on the planetary health diet: 2 days with only low-quality (LQ) protein sources and 2 days with low + high-quality (HQ) protein sources. The protein quality of Day 1LQ (DIAAS 76, PDCAAS 88) was increased by the addition of high-quality protein sources (HQPS): Day 1HQ (DIAAS 94, PDCAAS 98). Day 2LQ had a low PQ (DIAAS 71, PDCAAS 74), but when HQPS were used (Day 2HQ), the PQ increased (DIAAS 83, PDCAAS 88). Scenarios (day 1HQ, day 1LQ, and day 2 HQ) were classified as of good PQ. However, day 1LQ had a low protein quality. Consuming HQPS in a vegan diet can help to fulfil the recommendation of essential amino acids. This work served to understand and apply methods to estimate protein quality that can be applied to optimize protein mixtures to fulfil amino acid requirements in the future.

An Evaluation of Probability of Adequate Nutrient Intake (PANDiet) Scores as a Diet Quality Metric in Irish National Food Consumption Data

Identifying reliable metrics which measure the quality of a diet to promote nutrient adequacy and long-term health is an important step in the development of a sustainable food system. The Probability of Adequate Nutrient Intake (PANDiet) scoring system has been used as a measure of dietary quality in interdisciplinary research in recent years. The aim of the current study is to apply the PANDiet scoring system, and to assess the validity of the score as a metric of nutritional adequacy, within the Irish population. The Irish National Adult Nutrition Survey is a representative database with detailed data on nutrient intakes (18−90 years; n = 1051 valid-reporters; 2008−2010) and biofluid analytes (blood n = 786; urine n = 778). The PANDiet scoring system was expanded to include seven macronutrients, twelve micronutrients, nine minerals, and total energy using an established methodology. PANDiet scores were assessed against the Alternate Healthy Eating Index (AHEI) and Alternate Mediterranean Diet (aMED) food-based scores. The average score for the population (μ) was 63.69 ± 0.23 and ranged from 38.27 to 89.74. Higher PANDiet scores were significantly associated with males, higher educated participants, non-smokers, and low-energy-dense diets (p < 0.001). Females between the ages of 18 and 35 had a significantly lower nutrient adequacy score (μ 59.17). PANDiet scores were significantly correlated with serum folate, riboflavin status, serum vitamin D (p < 0.05) and with AHEI and aMED scores (Rs 0.45 and 0.43, p < 0.0001). The nutritional contribution of food groups varied between genders and low, moderate, and high nutritional adequacy groups. The PANDiet scoring system facilitated a detailed analysis of nutritional adequacy across sub-groups of the population, and is a comprehensive and valid diet quality metric in Irish databases.

Contrary to ultra-processed foods, the consumption of unprocessed or minimally processed foods is associated with favorable patterns of protein intake, diet quality and lower cardiometabolic risk in French adults (INCA3)

PURPOSE

While the consumption of ultra-processed foods is steadily increasing, there is a growing interest in more sustainable diets that would include more plant protein. We aimed to study associations between the degree of food processing, patterns of protein intake, diet quality and cardiometabolic risk.

METHODS

Using the NOVA classification, we assessed the proportion of energy from unprocessed/minimally processed foods (MPFp), processed foods (PFp) and ultra-processed foods (UPFp) in the diets of 1774 adults (18-79 years) from the latest cross-sectional French national survey (INCA3, 2014-2015). We studied the associations between MPFp, PFp and UPFp with protein intakes, diet quality (using the PANDiet scoring system, the global (PDI), healthful (hPDI) and unhealthful (uPDI) plant-based diet indices) and risk of cardiometabolic death (using the EpiDiet model).

RESULTS

MPFp was positively associated with animal protein intake and plant protein diversity, whereas PFp was positively associated with plant protein intake and negatively with plant protein diversity. The PANDiet was positively associated with MPFp (β = 0.14, P < 0.0001) but negatively with UPFp (β = - 0.05, P < 0.0001). These associations were modified by adjustment for protein intakes and plant protein diversity. As estimated with comparative risk assessment modeling between extreme tertiles of intake, mortality from cardiometabolic diseases would be decreased with higher MPFp (e.g. by 31% for ischemic heart diseases) and increased with higher UPFp (by 42%) and PFp (by 11%).

CONCLUSIONS

In the French population, in contrast with UPFp, higher MPFp was associated with higher animal protein intake, better plant protein diversity, higher diet quality and markedly lower cardiometabolic risk.

Measuring Dietary Botanical Diversity as a Proxy for Phytochemical Exposure

The study of natural plant molecules and their medicinal properties, pharmacognosy, provides a taxonomy for botanical families that represent diverse chemical groupings with potentially distinct functions in relation to human health. Yet, this reservoir of knowledge has not been systematically applied to elucidating the role of patterns of plant food consumption on gut microbial ecology and function. All chemical classes of dietary phytochemicals can affect the composition of the microbes that colonize the gut and their function. In turn, the gut microbiome affects the host via multiple mechanisms including gut barrier function, immune function, satiety and taste regulation and the activity of biological signaling pathways that influence health and disease. Herein, we report the development of a botanical diversity index (BDI) to evaluate plant food consumption as a novel metric for identifying and quantifying phytochemicals to which an individual is exposed. A rationale is advanced for using the BDI to investigate how plant food diversity impacts gut microbial ecology and functionality.

An examination of contributions of animal- and plant-based dietary patterns on the nutrient quality of diets of adult Canadians

Dietary guidance and Canada's 2019 Food Guide encourage increased consumption of plant-based foods as a source of dietary protein. However, there is an absence of recent data on protein and nutrient intakes and quality of Canadian dietary patterns that might occur with increased plant protein intakes. This study compared food sources and nutrient intakes of Canadian adults within groups of increasing plant protein-containing diets. The CCHS 2015 Public-Use Microdata File of single 24-hour dietary recalls of males and females ≥19 years (n = 6498) or ≥70 years (n = 1482) were examined. Respondents were allocated into 4 groups defined by their protein intake percentage coming from plant-based foods (i.e., group 1: 0-24.9%, group 2: 25-49.9%, group 3: 50-74.9%, group 4: 75-100%). Protein intake in adults averaged 63.3% animal and 36.7% plant protein. Where plant protein contributed >50% protein, higher intakes of carbohydrate, dietary fibre, folate, dietary folate equivalents, iron and magnesium (p < 0.001) but lower intakes of total and saturated fat, protein, vitamin D, vitamin B12, riboflavin and niacin (p < 0.0001) were reported. In contrast, group 1 had higher total and saturated fat, protein, vitamin B12, thiamin, niacin, and zinc, but lower carbohydrate, dietary fibre, and magnesium. Balancing plant- with animal-based protein foods leads to healthier dietary patterns with more favourable nutritional properties when compared with diets based on either high animal or high plant protein content. Novelty: Combinations of animal- and plant-based proteins improve nutrient quality of Canadian diets. The source of protein influences diet quality.

Protein for a Healthy Future: How to Increase Protein Intake in an Environmentally Sustainable Way in Older Adults in the Netherlands

BACKGROUND

Protein intake greater than the currently recommended amount is suggested to improve physical functioning and well-being in older adults, yet it is likely to increase diet-associated greenhouse gas emissions (GHGEs) if environmental sustainability is not considered.

OBJECTIVES

We aimed to identify dietary changes needed to increase protein intake while improving diet environmental sustainability in older adults.

METHODS

Starting from the habitual diet of 1,354 Dutch older adults (aged 56-101 y) from the Longitudinal Aging Study Amsterdam cohort, mathematical diet optimization was used to model high-protein diets with minimized departure from habitual intake in cumulative steps. First, a high-protein diet defined as that providing ≥1.2 g protein · kg body weight-1 · d-1 was developed isocalorically while maintaining or improving nutritional adequacy of the diet. Second, adherence to the Dutch food-based dietary guidelines (FBDG) was imposed. Third, a stepwise 10% GHGE reduction was applied.

RESULTS

Achieving a high-protein diet aligned with the FBDG without considering GHGEs required an increase in vegetables, legumes, nuts, whole grains, meat/dairy alternatives, dairy, and eggs and a reduction in total meat (for men only) and discretionary products, but it resulted in a 5% increase in GHGEs in men and 9% increase in women. When a stepwise GHGE reduction was additionally applied, increases in poultry and pork (mainly for women) and decreases in beef/lamb and processed meat were accrued, with total meat staying constant until a 50-60% GHGE reduction. Increases in whole grains, nuts, and meat/dairy alternatives and decreases in discretionary products were needed to lower GHGEs.

CONCLUSIONS

A high-protein diet aligned with FBDG can be achieved in concert with reductions in GHGEs in Dutch older adults by consuming no more than the recommended 500 g meat per week while replacing beef and lamb and processed meat with poultry and pork and increasing intake of diverse plant-protein sources.

Fish as an alternative protein - A consumer-oriented perspective on its role in a transition towards more healthy and sustainable diets

Fish has several benefits that make it a desirable part of a healthy diet. It is also a high-protein product that can be used as a relatively efficient meat replacer. Both from a health and sustainability perspective, however, it is important to consider the optimum number of fish servings per week and to examine whether fish and plant protein can be brought under the same heading of alternative protein sources. To explore the consumer perspective on these issues, this paper draws on a brief literature study and a re-analysis of survey data from the Netherlands collected earlier. The hypothesis was that affinities with fish consumption and plant-based protein sources are to a certain extent related to each other, based on common relationships with food involvement, which set them apart from meat. The results showed that the hypothesis needed to be nuanced: fish consumption was associated exclusively with affinity with spicy meals based on authentic plant protein sources (e.g. nuts) and this relationship was partially based on food involvement. The results are in line with current Dutch recommendations that encourage consumers to eat one serving of fish per week and that stimulate those who already eat more than one serving of fish to replace the rest by plant-based protein sources.

Nutritional Quality of Vegetarian and Non-Vegetarian Dishes at School: Are Nutrient Profiling Systems Sufficiently Informative?

In France, school canteens must offer a vegetarian meal at least once per week. The objective was to evaluate the nutritional quality of school main dishes. A database of main dishes served in primary schools was first split into non-vegetarian (n = 669) and vegetarian (n = 315) categories. The latter has been divided into three sub-categories: vegetarian dishes containing cheese, vegetarian dishes containing eggs and/or dairy products but no cheese and vegetarian dishes without any eggs, cheese or other dairy products (vegan). Categories and sub-categories were compared based on nutrient adequacy ratios for "protective" nutrients (proteins, fibres, vitamins, minerals, essential fatty acids), the contents of nutrients to be limited (saturated fatty acids (SFA), sodium, free sugars) and on two nutrient profiling systems (SAIN,LIM and Nutri-Score). The vegetarian category and the non-vegetarian category displayed "adequate" levels (≥5% adequacy for 100 kcal) on average for almost all "protective" nutrients. The three sub-categories of vegetarian dishes displayed good SAIN,LIM and Nutri-Score profiles on average, although key nutrients were lacking (vitamin B12, vitamin D and DHA) or were present in insufficient amounts (vitamin B2 and calcium) in the vegan sub-category. The sub-category containing eggs and/or dairy products other than cheese was a good compromise, as it provided protective nutrients associated with eggs and fresh dairy products, while the sub-category containing cheese provided higher levels of SFA. Nutrient profile algorithms are insufficiently informative to assess the nutritional quality of school dishes.