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

Modelling the impact of substituting meat and dairy products with plant-based alternatives on nutrient adequacy and diet quality

BACKGROUND

Novel plant-based meat and dairy alternatives are designed to mimic and replace animal sourced products, yet their nutritional composition differs to traditional alternatives such as legumes and beans. The nutritional impacts of switching from animal sourced to traditional or novel plant-based alternatives remains unclear.

OBJECTIVE

To model the impact of partial and complete substitution of animal sourced meat and dairy products with traditional or novel plant-based alternatives on diet quality and nutrient adequacy in a nationally representative sample of Australian adults.

METHODS

Dietary data (one 24-hour recall) from the Australian Health Survey 2011-2013 (n=9115; ≥19 years) were analysed. Four models simulated partial or complete substitution of animal sourced meat and dairy with traditional or novel plant-based alternatives. Diet quality was assessed using the Dietary Guideline Index (DGI), and nutrient adequacy was determined using age and sex-specific nutrient reference values. Modelled diets were compared to a baseline diet using survey weighted paired t-tests.

RESULTS

DGI scores improved by between 0.3% to 6.0% for all models across all sex and age groups compared to baseline. Improvements in diet quality were greatest for the complete substitution to traditional alternatives (5.1% average increase in DGI). Overall, inclusion of plant-based alternatives (complete or partial) decreased saturated fat and increased dietary fibre. Long-chain n-3 polyunsaturated fatty acids decreased to below adequate intakes for all complete substitution models. Substitution with traditional alternatives deceased sodium and increased calcium, while substitution with novel alternatives increased sodium and decreased calcium.

CONCLUSIONS

All models using traditional alternatives, and the partial substitution using novel alternatives showed small but statistically significant improvements in diet quality. Nutrient adequacy varied between models, with nutrients including saturated fat, sodium, calcium, and long-chain fatty acids implicated. Findings highlight the importance of informed choices when switching to traditional or novel plant-based alternatives to prevent sub-optimal dietary intake.

Impact of a daily legume-based meal on blood and anthropometric parameters in a group of omnivorous adults: A pilot study

This pilot study aimed to assess the impact of substituting a traditional lunch for a vegetarian legume-based meal on blood and anthropometric parameters in a group of omnivorous adults. A one-group comparison, quasi-experimental dietary intervention was designed. A vegetarian legume-based meal was offered for 8 consecutive weeks (weekdays) to non-vegetarian individuals (n = 26), (28 years [P25 = 20.0, P75 = 35.5]; 21.9 kg/m2 [P25 = 21.3, P75 = 24.8]). Sociodemographic data, health status and lifestyle-related information were recorded. Three-day food records were used to collect food intake at baseline and at the end of the intervention. Anthropometric parameters were recorded and fasting blood analyses were performed following standard procedures. Wilcoxon signed-rank test was used for statistical comparisons. A p-value <0.05 was considered statistically significant. Participants showed a median intake of 79.8 g of cooked legumes per meal, meaning 13 (50.0%) subjects met the Portuguese daily legume intake recommendations during the intervention days. There were no statistically significant differences in anthropometric parameters. Transferrin concentration increased after 8 weeks (+12.5 mg/dL; p = 0.001). Total cholesterol concentration reduced after 8 weeks (-6 mg/dL; p = 0.041), as well as low-density lipoprotein (LDL) cholesterol (-7 mg/dL; p = 0.003). Triglycerides (+9 mg/dL; p = 0.046), fasting glucose (+2 mg/dL; p = 0.037) and HbA1c (+0.1 mg/dL; p = 0.010) concentration increased after the 2-month legume-based trial. Results suggest a cholesterol-lowering potential of legume-rich diets. However, unfavourable results regarding the impact on glucose metabolism-related biomarkers and triglyceride levels were observed. The study's limitations in design and sample size emphasise the importance of conducting further research with larger cohorts to attain more conclusive findings.

Evaluation of Protein Adequacy From Plant-Based Dietary Scenarios in Simulation Studies: A Narrative Review

Although a diet high in plant foods can provide beneficial nutritional outcomes, unbalanced and restrictive plant-based diets may cause nutrient deficiencies. Protein intake from these diets is widely discussed, but the comparison of animal and plant proteins often disregards amino acid composition and digestibility as measurements of protein quality. Poor provision of high-quality protein may result in adverse outcomes, especially for individuals with increased nutrient requirements. Several dietary modeling studies have examined protein adequacy when animal-sourced proteins are replaced with traditional and novel plant proteins, but no review consolidating these findings are available. This narrative review aimed to summarize the approaches of modeling studies for protein intake and protein quality when animal-sourced proteins are replaced with plant foods in diet simulations and examine how these factors vary across age groups. A total of 23 studies using dietary models to predict protein contribution from plant proteins were consolidated and categorized into the following themes-protein intake, protein quality, novel plant-based alternatives, and plant-based diets in special populations. Protein intake from plant-based diet simulations was lower than from diets with animal-sourced foods but met country-specific nutrient requirements. However, protein adequacy from some plant-sourced foods were not met for simulated diets of children and older adults. Reduced amino acid adequacy was observed with increasing intake of plant foods in some scenarios. Protein adequacy was generally dependent on the choice of substitution with legumes, nuts, and seeds providing greater protein intake and quality than cereals. Complete replacement of animal to plant-sourced foods reduced protein adequacy when compared with baseline diets and partial replacements.

Protein - a scoping review for Nordic Nutrition Recommendations 2023

Proteins are needed for providing essential amino acids, nitrogen, and fuel for the body's needs in all age groups. Proteins are especially required during active growth in pregnancy, lactation, childhood, and tissue growth in general. An adequate protein intake is needed in old adults to avoid premature muscle loss. According to the current dietary surveys, protein intake in the Nordic and Baltic countries varies from 15 to 19% of the total energy intake in adults. Comprehensive data regarding children and older adults are lacking. No good measure for protein status exists, and the estimation of physiological requirements is based on N-balance studies having some weaknesses. Protein quality is assessed by considering the protein digestibility of individual indispensable amino acids and their utilization (bioavailability), which is affected by food antinutrients and processing. The evidence regarding the association of protein intake per se with health outcomes is limited or suggestive. It is difficult to separate from the effect of other nutrients or ingredients in protein-rich foods. Proteins are widespread in foods, deriving from both animal and plant sources. Animal-sourced protein production puts more strain on the environment than plant-sourced proteins and contributes significantly to greenhouse gas emissions, thereby enhancing climate change. In Nordic and Baltic countries, consumption of animal-sourced proteins is relatively high. A shift toward more plant-based protein diets would be advisable for promoting a healthy and sustainable diet.

Associations of food motives with red meat and legume consumption in the population-based DILGOM study

PURPOSE

To improve human health and environmental sustainability, red meat consumption should decrease and legume consumption increase in diets. More information on food motives, however, is required when developing more tailored and effective interventions targeting legume and meat consumption. We aimed to examine the associations between food motives and red meat and legume consumption, and whether these associations differ between different subgroups (gender, age groups, marital status, education, BMI).

METHODS

Ten food motives (health, mood, convenience, sensory appeal, natural content, price-cheap, price-value, weight control, familiarity and ethical concern measured with Food Choice Questionnaire) were studied in 3079 Finnish adults in the population-based DILGOM study. Food consumption was assessed with Food Frequency Questionnaire. The adjusted estimates from multivariable regression models are reported.

RESULTS

Higher relative importance of natural content (β = - 0.275, 95% CI - 0.388; - 0.162) and ethical concern (β = - 0.462, 95% CI - 0.620; - 0.305) were associated with lower red meat consumption, and higher appreciation of sensory appeal (β = 0.482, 95% CI 0.347; 0.616) and price-cheap (β = 0.190, 95% CI 0.099; 0.281) with higher red meat consumption. Higher importance of health (β = 0.608, 95% CI 0.390; 0.825) was associated with higher legume consumption, and higher appreciation of convenience (β = - 0.401, 95% CI - 0.522; - 0.279), price-value (β = - 0.257, 95% CI - 0.380; - 0.133) and familiarity (β = - 0.278, 95% CI - 0.393; - 0.164) with lower legume consumption. The associations of particularly ethical concern, weight control, sensory appeal and mood varied according to gender, age, marital status or BMI.

CONCLUSION

The development and implementation of actions to decrease red meat and increase legume consumption should focus on several food motives across different subgroups.

The impacts of partial replacement of red and processed meat with legumes or cereals on protein and amino acid intakes: a modelling study in the Finnish adult population

BACKGROUND

A shift towards more plant-based diets is considered healthy and environmentally sustainable but may cause a concern regarding protein and amino acid intakes. This modelling study aimed to assess the impacts of partial replacement of red and processed meat with legumes or cereals on the protein and indispensable amino acid intakes in the Finnish adult population.

MATERIALS AND METHODS

We used the cross-sectional data of the National FinDiet 2017 Survey (two non-consecutive 24-h recalls, n = 1655, 47% men, aged 18-74 years). Six replacement scenarios were created in which the amount of red and processed meat exceeding 70 g/day (Finnish nutrition recommendation), or 30 g/day (EAT-Lancet recommendation) was replaced with the same amounts of legumes, cereals or their combination. Differences to the reference diet were evaluated based on non-overlapping 95% confidence intervals. Population shares (%) below estimated average requirements (EAR) were calculated using the usual intake modelling methodology (SPADE).

RESULTS

The replacement scenarios decreased the protein and indispensable amino acid intakes depending on gender and age. At the 70-g level, decreases were observed only in men aged 18-64 years. At the 30-g level, decreases were observed in other gender and age groups except women aged 65-74 years. In the scenarios, the mean daily protein intake was 15-18% of total energy intake (E%) (reference 17-18 E%), and the proportions below the EAR were 7-10% in men and 8-10% in women aged 18-64 years (reference 5-7%) and 20-25% in men and 16-20% in women aged 65-74 years (reference 14-17%). For total indispensable amino acids, the proportions below the EAR were <5% in the reference diet and the scenarios.

CONCLUSIONS

The mean daily protein intake remained sufficient when red and processed meat was partially replaced with legumes or cereals in the Finnish adult population. However, protein adequacy in the elderly population warrants attention and more research.

Association between legume consumption and the intake of other foods and nutrients in the Finnish adult population

The role of legumes in healthy and sustainable diets is increasingly of interest. Few studies have investigated the association between legume consumption and the consumption of other food groups and the intake of nutrients. This study examined how legume consumption is associated with the consumption of other foods and the intake of nutrients among Finnish adults. Our study used cross-sectional data from the population-based FinHealth 2017 Study consisting of 2250 men and 2875 women aged ≥18 years. The associations between legume consumption (quartile classification), food groups and nutrients were analysed using multivariable linear regression. The models were initially adjusted for energy intake and additionally for age, educational level, smoking status, leisure-time physical activity and BMI. Legume consumption had a positive association with age, education level and leisure-time physical activity. The consumption of legumes was positively associated with the consumption of fruits and berries, vegetables, nuts and seeds and fish and fish products and inversely associated with the consumption of red and processed meat, cereals and butter and butter-based fat spreads. Furthermore, legume consumption was positively associated with the intake of protein, fibre, folate, thiamine and salt in both sexes and inversely associated with the intake of saturated fatty acids and sucrose (sucrose, women only). Thus, legume consumption appears to reflect overall healthier food choices. An increase in legume consumption could accelerate the transition to more sustainable diets. The confounding role of other foods and nutrients should be considered when studying associations between legume consumption and health outcomes.