Shifting towards optimized healthy and sustainable Dutch diets: impact on protein quality

PURPOSE

To reduce the environmental impact of Western diets, a reduction of meat consumption and a substitution by plant-based protein sources is needed. This protein transition will affect the quantity and quality of dietary protein. Therefore, the aim of this study was to evaluate the protein adequacy of diets optimized for nutritional health and diet-related greenhouse gas emission (GHGE).

METHODS

Data from 2150 adult participants of the Dutch National Food Consumption Survey were used, with diet assessed using two non-consecutive 24 h dietary recalls. Utilizable protein of current diets per day was based on meal composition and the Protein Digestibility-Corrected Amino Acid Score and was compared to protein requirements. Optimized diets were derived as linear combinations of current diets that minimized GHGE and maximized the Dutch Healthy Diet 2015 score, with/without constraints to keep dietary change within 33% of current consumption. Protein adequacy was evaluated in both current and optimized diets.

RESULTS

In all age and gender strata, the healthiest diets had higher GHGE, the most sustainable diets had the lowest dietary quality, though higher than current diets, and protein adequacy remained sufficient. When limiting dietary change to 33% of current consumption, in the most promising trade-off diet GHGE was reduced by 12-16%. The current diet provided 1.4-2.2 times the required amount of utilizable protein.

CONCLUSION

These results suggest that a realistic aim for the next decade might be to reduce diet-related GHGE to 12-16% of the current levels without compromising protein adequacy and diet quality. To achieve global targets, upstream food system transformations are needed with subsequent dietary changes.

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.

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.

The potential benefits of dietary shift in China: Synergies among acceptability, health, and environmental sustainability

The transition to a healthier diet recommended by national dietary guidelines in China may not achieve sufficient environmental benefits. This study assesses China's potential of transforming into a sustainable diet and the trade-offs among reducing food-related environmental impacts, improving nutritional quality and respecting eating habits. We used multi-objective optimization to build optimized scenarios, with the lowest environmental footprint and greatest acceptability (i.e., with the minimum departure from the currently observed diet) as optimization goals, and adequate macro- and micronutrient intake levels as constraints. In doing so, we assessed the actual benefits and synergies of reducing carbon footprint (CF), water footprint (WF), and ecological footprint (EF) and improving health and respecting dietary acceptance under the corresponding scenarios. The results show that CF, WF and EF can be reduced by up to 19%, 15% and 30% respectively, while satisfying nutritional constraints and achieving the minimum deviation from the current food combination. The greatest synergistic benefits for CF, WF and EF are achieved when the minimum CF is the optimization goal; the maximum synergistic benefits for the environment, health and acceptability are achieved when the CF is reduced by 10%. Our findings identify the trade-offs and synergies dietary changes considering nutritional benefits, environmental sustainability and acceptability, and reveal the challenges and opportunities for achieving such synergies.

Diet shift: Considering environment, health and food culture

Most studies have suggested that dietary choices have effects on both the environment and human health; however, they have ignored food culture, which is both an "independent variable" and a "dependent variable" of diet choice. The purpose of this study is to explore a diet optimization path that meets nutritional needs and has little impact on the environment, while respecting the local food culture to a large extent. We took China's Xinjiang Uygur autonomous region (hereinafter referred to as "Xinjiang") as the case area because Xinjiang is a multiethnic region with a unique food culture characterized by a high proportion of mutton in meat. According to the study's calculation, the current diet in Xinjiang has a high carbon footprint (CF), water footprint (WF) and ecological footprint (EF) and does not present the nutritional structure of a balanced diet. Considering the trade-offs among environmental carrying capacity, health and food culture is the challenge of changing the local food structure. With the method of multi-objective optimization, we propose "optimal diets", which show potential for mitigating environmental impacts and improving the state of health. Most importantly, one of the optimized diets is most desirable because it considers the preservation of the existing food culture. This study demonstrates the feasibility of providing a route for diet transformation that has double benefits regarding the environment and health, or even triple benefits regarding the environment, health and cultural acceptability.

A practical solution to improve the nutritional balance of Korean dine-out menus using linear programming

OBJECTIVE

We analysed optimal nutrient levels using linear programming (LP) to reveal nutritional shortcomings of Korean dine-out meals and to stress the importance of fruits and dairy products for maintaining a healthy diet.

DESIGN

LP models that minimize deviation from recommended nutrient values were formulated to analyse deficiency or excess of nutrients under the best situation.

SETTING

Korean dine-out menus and nutritional information were taken from the nutrient composition tables for dine-out menus developed by the Ministry of Food and Drug Safety and the nutrient database from Computerized Analysis Program. Acceptable macronutrient distribution ranges of macronutrients such as carbohydrate, protein and fat, and recommended intake levels for energy, vitamins, minerals and cholesterol, by sex, were based on the Dietary Reference Intake for Koreans aged 30-49 years.ParticipantsOptimization was performed on selecting the optimal Korean meal combination.

RESULTS

LP optimization models showed that it is unlikely to satisfy all nutrient recommendations with any combination of dine-out menus. Specifically, meal combinations of Korean dine-out menus had high levels of Na and cholesterol and low levels of vitamins and minerals. Four formulations were considered to compare the effects of controlling Na and including fruit and dairy products. The unbalanced diet was resolved with extra consumption of fruits and dairy products.

CONCLUSIONS

The best meal combination in dine-out menus, even though the proportion and pairing of menus may be unrealistic, is not healthy, and thus one should consume fruits and dairy products to maintain a balanced diet.

Response to dietary carbohydrates in European seabass (Dicentrarchus labrax) muscle tissue as revealed by NMR-based metabolomics

INTRODUCTION

Feed optimization is a key step to the environmental and economic sustainability of aquaculture, especially for carnivorous species. Plant-derived ingredients can contribute to reduce costs and nitrogenous effluents while sparing wild fish stocks. However, the metabolic use of carbohydrates from vegetable sources by carnivorous fish is still not completely understood.

OBJECTIVES

We aimed to study the effects of diets with carbohydrates of different digestibilities, gelatinized starch (DS) and raw starch (RS), in the muscle metabolome of European seabass (Dicentrarchus labrax).

METHODS

We followed an NMR-metabolomics approach, using two sample preparation procedures, the intact muscle (HRMAS) and the aqueous muscle extracts (¹H NMR), to compare the variations in muscle metabolome between the two diets.

RESULTS

In muscle, multivariate analysis revealed similar metabolome shifts for DS and RS diets, when compared with the control diet. HRMAS of intact muscle, which included both hydrophobic and hydrophilic metabolites, showed increased lipid in DS-fed fish by univariate analysis. Regardless of the nature of the starch, increased glycine and phenylalanine, and decreased proline were observed when compared to the Ctr diet. Combined univariate analysis of intact muscle and aqueous extracts indicated specific diet related changes in lipid and amino acid metabolism, consistent with increased dietary carbohydrate supplementation.

CONCLUSIONS

Due to differential sample processing, outputs differ in detail but provide complementary information. After tracing nutritional alterations by profiling fillet components, DS seems to be the most promising alternative to fishmeal-based diets in aquaculture. This approach should be reproducible for other farmed fish species and provide valuable information on nutritional and organoleptic properties of the final product.

Food choices to meet nutrient recommendations for the adult Brazilian population based on the linear programming approach

OBJECTIVE

To identify optimal food choices that meet nutritional recommendations to reduce prevalence of inadequate nutrient intakes.

DESIGN

Linear programming was used to obtain an optimized diet with sixty-eight foods with the least difference from the observed population mean dietary intake while meeting a set of nutritional goals that included reduction in the prevalence of inadequate nutrient intakes to ≤20 %.

SETTING

Brazil.

SUBJECTS

Participants (men and women, n 25 324) aged 20 years or more from the first National Dietary Survey (NDS) 2008-2009.

RESULTS

Feasible solution to the model was not found when all constraints were imposed; infeasible nutrients were Ca, vitamins D and E, Mg, Zn, fibre, linolenic acid, monounsaturated fat and Na. Feasible solution was obtained after relaxing the nutritional constraints for these limiting nutrients by including a deviation variable in the model. Estimated prevalence of nutrient inadequacy was reduced by 60-70 % for most nutrients, and mean saturated and trans-fat decreased in the optimized diet meeting the model constraints. Optimized diet was characterized by increases especially in fruits (+92 g), beans (+64 g), vegetables (+43 g), milk (+12 g), fish and seafood (+15 g) and whole cereals (+14 g), and reductions of sugar-sweetened beverages (-90 g), rice (-63 g), snacks (-14 g), red meat (-13 g) and processed meat (-9·7 g).

CONCLUSION

Linear programming is a unique tool to identify which changes in the current diet can increase nutrient intake and place the population at lower risk of nutrient inadequacy. Reaching nutritional adequacy for all nutrients would require major dietary changes in the Brazilian diet.

The environmental cost of subsistence: Optimizing diets to minimize footprints

The question of how to minimize monetary cost while meeting basic nutrient requirements (a subsistence diet) was posed by George Stigler in 1945. The problem, known as Stigler's diet problem, was famously solved using the simplex algorithm. Today, we are not only concerned with the monetary cost of food, but also the environmental cost. Efforts to quantify environmental impacts led to the development of footprint (FP) indicators. The environmental footprints of food production span multiple dimensions, including greenhouse gas emissions (carbon footprint), nitrogen release (nitrogen footprint), water use (blue and green water footprint) and land use (land footprint), and a diet minimizing one of these impacts could result in higher impacts in another dimension. In this study based on nutritional and population data for the United States, we identify diets that minimize each of these four footprints subject to nutrient constraints. We then calculate tradeoffs by taking the composition of each footprint's minimum diet and calculating the other three footprints. We find that diets for the minimized footprints tend to be similar for the four footprints, suggesting there are generally synergies, rather than tradeoffs, among low footprint diets. Plant-based food and seafood (fish and other aquatic foods) commonly appear in minimized diets and tend to most efficiently supply macronutrients and micronutrients, respectively. Livestock products rarely appear in minimized diets, suggesting these foods tend to be less efficient from an environmental perspective, even when nutrient content is considered. The results' emphasis on seafood is complicated by the environmental impacts of aquaculture versus capture fisheries, increasing in aquaculture, and shifting compositions of aquaculture feeds. While this analysis does not make specific diet recommendations, our approach demonstrates potential environmental synergies of plant- and seafood-based diets. As a result, this study provides a useful tool for decision-makers in linking human nutrition and environmental impacts.

Foraging strategies and seasonal diet optimization of muskoxen in West Greenland

Various aspects of optimal foraging and seasonal diet composition of bulls (bachelor and dominant), cows, subadults, and yearlings of muskoxen Ovibos moschatus were investigated in West Greenland during the following seasons: calving, post-calving, summer, rut and mid-winter. The following hypotheses were tested: (1) muskoxen maximize daily energy intake during spring and summer, (2) dominant bulls monopolizing cows during the rutting season shift from an energy maximizing to a time minimizing foraging strategy in order to maximize the time available for reproductive activities, and (3) muskoxen employ a time minimizing foraging strategy during winter to conserve energy. As forage quality changed throughout the short Arctic growing season, muskoxen responded by changing the proportions of daily time spent feeding on graminoids (Cyperaceae, Poaceae) and dicots (Salix, Betula), respectively. This seasonal variation in the relative proportion of daily feeding time spent ingesting graminoids followed approximately the energy maximization prediction over the periods calving to rut. Neither time minimizing nor random foraging could explain the observed diets in this period, thus confirming hypothesis 1. Dominant bulls did not shift to the time minimizing strategy as predicted by hypothesis 2. However, during the pre-rutting and rutting seasons bulls deviated from the other sex/age classes by failing to obtain the daily maximum energy predicted by the model, as a result of a higher proportion of time allocated to agonistic and sexual behaviour. During winter, none of the sex/age classes employed a time minimizing strategy, so rejecting hypothesis 3. Instead, muskoxen were found to maximize Na intake, indicating that Na is of major importance for winter survival. The results emerging from a linear programming model with constraint settings varying over seasons confirm that the constraint parameters applied are indeed important limiting factors for muskoxen in natural populations.