Planet-based diets: improving environmental sustainability of healthy diets.

The focus of nutritionists is on improvement of the health impact of current diets. Therefore, it is important to ask the question whether healthy diets are more sustainable. This review provides an overview on the research on synergies between health and sustainability. Synergies are found from shifts from animal-based to plant-based diets, from ultra-processed foods to fresh and whole foods and from reduction of food waste. The importance of looking at sustainability of the present diets has led to steps made in Europe to incorporate sustainability into food-based dietary guidelines. Examples from UK, Nordics, Belgium and the Netherlands are given. World Wildlife Fund has summarised the insides in a future-proof diet: the planet-based diet within planetary boundaries.

Corrigendum: A Review of the Use of Linear Programming to Optimize Diets, Nutritiously, Economically and Environmentally.

[This corrects the article DOI: 10.3389/fnut.2018.00048.].

A Food System Approach for Sustainable Food-Based Dietary Guidelines: An Exploratory Scenario Study on Dutch Animal Food Products.

This study explores interconnections between food consumption and production of animal (by-)products in different food system scenarios within the scope of Dutch Food-Based Dietary Guidelines (FBDG). For this scenario study, a Microsoft Excel model was created that include seven scenarios with different quantities of eggs, milk, cheese, beef cattle, broilers, and pigs as input. Number of animals, intake of energy, animal protein, saturated fatty acids (SFAs), trans-fatty acids (TFAs), salt, greenhouse gas emissions (GHGEs), and land use (LU) were calculated and compared with current consumption and reference values. Based on the concept of eating the whole animal, every recommended lean, unprocessed portion of beef comes along with a non-recommended portion of beef (two portions for pork, 0.5 portion for broilers). The reference values for SFAs, TFAs, and salt were not exceeded if the intake of meat is limited to 410 g/week. The scenarios with recommended 450 mL semi-skimmed milk and 40 g/day low-fat cheese results in 36 g/day of butter as by-product, exceeding its acceptable intake three times. The near-vegetarian scenario with recommended amounts of eggs, milk, and cheese, includes only a portion of beef/calf per 6 days and a portion of chicken per 9 weeks as by-products. This scenario more than halves the GHGE and LU. Finally, the scenario that included the maximum recommended amounts of animal products is reachable with half the current size of Dutch livestock. This conceptual framework may be useful in the discussion on how future sustainable FBDG can incorporate a more food system-based approach.

Integration of various dimensions in food-based dietary guidelines via mathematical approaches: report of a DGE/FENS Workshop in Bonn, Germany, 23-24 September 2019.

In the past, food-based dietary guidelines (FBDGs) were derived nearly exclusively by using systematic reviews on diet-health relationships and translating dietary reference values for nutrient intake into foods. This approach neglects many other implications that dietary recommendations have on society, the economy and environment. In view of pressing challenges, such as climate change and the rising burden of diet-related diseases, the simultaneous integration of evidence-based findings from different dimensions into FBDGs is required. Consequently, mathematical methods and data processing are evolving as powerful tools in nutritional sciences. The possibilities and reasons for the derivation of FBDGs via mathematical approaches were the subject of a joint workshop hosted by the German Nutrition Society (DGE) and the Federation of European Nutrition Societies (FENS) in September 2019 in Bonn, Germany. European scientists were invited to discuss and exchange on the topics of mathematical optimisation for the development of FBDGs and different approaches to integrate various dimensions into FBDGs. We concluded that mathematical optimisation is a suitable tool to formulate FBDGs finding trade-offs between conflicting goals and taking several dimensions into account. We identified a lack of evidence for the extent to which constraints and weights for different dimensions are set and the challenge to compile diverse data that suit the demands of optimisation models. We also found that individualisation via mathematical optimisation is one perspective of FBDGs to increase consumer acceptance, but the application of mathematical optimisation for population-based and individual FBDGs requires more experience and evaluation for further improvements.

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.

Effect of food-related behavioral activation therapy on food intake and the environmental impact of the diet: results from the MooDFOOD prevention trial.

PURPOSE: Food-based dietary guidelines are proposed to not only improve diet quality, but to also reduce the environmental impact of diets. The aim of our study was to investigate whether food-related behavioral activation therapy (F-BA) applying Mediterranean-style dietary guidelines altered food intake and the environmental impact of the diet in overweight adults with subsyndromal symptoms of depression. METHODS: In total 744 adults who either received the F-BA intervention (F-BA group) or no intervention (control group) for 12 months were included in this analysis. Food intake data were collected through a food frequency questionnaire at baseline and after 6 and 12 months. Greenhouse gas emissions (GHGE), land use (LU), and fossil energy use (FEU) estimates from life-cycle assessments and a weighted score of the three (pReCiPe score) were used to estimate the environmental impact of each individual diet at each timepoint. RESULTS: The F-BA group reported increased intakes of vegetables (19.7 g/day; 95% CI 7.8-31.6), fruit (23.0 g/day; 9.4-36.6), fish (7.6 g/day; 4.6-10.6), pulses/legumes (4.0 g/day; 1.6-6.5) and whole grains (12.7 g/day; 8.0-17.5), and decreased intake of sweets/extras (- 6.8 g/day; - 10.9 to - 2.8) relative to control group. This effect on food intake resulted in no change in GHGE, LU, and pReCiPe score, but a relative increase in FEU by 1.6 MJ/day (0.8, 2.4). CONCLUSIONS: A shift towards a healthier Mediterranean-style diet does not necessarily result in a diet with reduced environmental impact in a real-life setting. TRIAL REGISTRATION: ClinicalTrials.gov. Number of identification: NCT02529423. August 2015.

Development of healthy and sustainable food-based dietary guidelines for the Netherlands.

OBJECTIVE: To derive healthy and sustainable food-based dietary guidelines (FBDG) for different target groups in the Netherlands and describe the process. DESIGN: Optimised dietary patterns for children, adolescents, adults and the elderly were calculated using an optimisation model. Foods high in saturated and trans-fatty acids, salt and sugar, and low in dietary fibre, were excluded. The dietary patterns resembled the current food consumption as closely as possible, while simultaneously meeting recommendations for food groups, nutrients, maximum limits for foods with a high environmental impact, and within 85 % of the energy requirement. Recommended daily amounts of food groups were based on the optimised dietary patterns and expert judgement. SETTING: The Netherlands. PARTICIPANTS: FBDG were derived for Dutch people with different ages, genders, activity levels and food preferences. RESULTS: For most target groups the optimisation model provided dietary patterns that complied with all requirements. For some food groups, the optimised amounts varied largely between target groups. For consistent messages to consumers, the optimised dietary patterns were adjusted to uniform recommendations per target group. Recommendations were visualised in the Wheel of Five. The advice is to eat the recommended amounts of foods according to the Wheel of Five and limit consumption of other foods. CONCLUSIONS: Based on an optimisation model, scientific evidence, information on dietary patterns and expert knowledge, we derived FBDG for different target groups. The Wheel of Five is a key food-counselling model that can help Dutch consumers to make their diets healthier and more environmentally sustainable.

Measuring food waste in Dutch households: A synthesis of three studies.

The aim of this study was to measure the food waste that occurs in Dutch households through a new, combined approach. The methods used were a sorting analysis of solid household waste from 130 households in 13 municipalities and a consumer survey given to 763 respondents. An estimation survey on liquid waste was given to 1105 respondents via a phone app. According to the consumer survey, consumers throw away 21.2 kg of food (solid and liquid) per person, per year. This appears to be an underestimation. The main part, 60.2%, is discarded via household waste, 29.6% goes down the sink or toilet and 10.2% is thrown away via other pathways. The sorting analysis shows that solid food waste (including sauces, fats and dairy products) via household waste amounts to 30.4 kilo per person, per year. Based on the distribution across the various pathways, it is calculated that 10.8 kg of solid food is wasted via other pathways. Together, this was 41.2 kg per person in 2016 (less than the 48 kg in 2010 and 47 kg in 2013). This decrease is not significant. Solid food waste accounts for 13.0% of all food purchased. The most wasted solid foods are bread (22%), dairy products (17%), vegetables (14%), fruit (12%) and meat (7%) ( See Table 1). A new method is used to estimate liquid waste via sinks and toilets; this waste amounts to 57.3 L per person, per year: 50.7 L of beverages (including milk) and 6.6 L of thick liquids. The waste volumes for coffee and tea (30.7 L) and milk (10 L) are large.

Development and Evaluation of the Eetmaatje Measuring Cup for Rice and Pasta as an Intervention to Reduce Food Waste.

Of all of the stages in the supply chain, more food waste comes from households than any other sector. A Dutch composition analysis showed that the solid food waste (including sauces, fats, and dairy products) from household waste amounted to 48.0 kg per person per year (in 2013), of which 5.0 kg consisted of cooked rice and pasta. These two product groups were numbers 1 and 3 in terms of relative waste: 34% of the purchased quantity of rice and 23% of that of pasta was wasted. Using questionnaires, we discovered that Dutch consumers mainly throw away food because they prepare too much of it. The same is true for rice and pasta because they increase greatly in volume when cooked. The water uptake ratio of rice is 2.5 (2.3-2.8) and that of pasta is 1.8 (1.5-2.3), which increases the chances of consumers overestimating portions. In 2013, more than half of the people surveyed did not measure pasta and rice portions. In view of this, the Netherlands Nutrition Centre developed a measuring cup called the Eetmaatje, which is marked with the recommended volumes for Dutch adults for different types of pasta and rice in terms of dry weight. The theoretical reduction of food waste the Eetmaatje provides is calculated to be ~6% for pasta and 21% for rice, or 12.5% combined. Between 2014 and 2019, more than 1.6 million Eetmaatje cups were distributed for free among Dutch households. Over that period, the measuring of pasta and rice by Dutch households increased. Most people (85-89%) in a panel of consumers who own an Eetmaatje think it is handy or very handy to use. The majority of those in the panel (50-80%) say that they use the Eetmaatje most times when they prepare a meal. Four out of five of those in the panel (77-87%) are convinced that the Eetmaatje helps them waste less pasta and rice. The Eetmaatje functions as a nudge to change cooking behavior and thus food waste behavior. Consumers who measure their pasta using the Eetmaatje self-reported that they produced less total food waste. The measured household waste of cooked rice and pasta seems to show a downward trend since the introduction of the cup. There is strong evidence that the Eetmaatje has increased the number of Dutch households measuring rice and pasta and thereby reducing food waste.

A Review of the Use of Linear Programming to Optimize Diets, Nutritiously, Economically and Environmentally.

The "Diet Problem" (the search of a low-cost diet that would meet the nutritional needs of a US Army soldier) is characterized by a long history, whereas most solutions for comparable diet problems were developed in 2000 or later, during which computers with large calculation capacities became widely available and linear programming (LP) tools were developed. Based on the selected literature (52 papers), LP can be applied to a variety of diet problems, from food aid, national food programmes, and dietary guidelines to individual issues. This review describes the developments in the search for constraints. After nutritional constraints, costs constraints, acceptability constraints and ecological constraints were introduced. The 12 studies that apply ecological constraints were analyzed and compared in detail. Most studies have used nutritional constraints and cost constraints in the analysis of dietary problems and solutions, but such research begin showing weaknesses under situations featuring a small number of food items and/or nutritional constraints. Introducing acceptability constraints is recommended, but no study has provided the ultimate solution to calculating acceptability. Future possibilities lie in finding LP solutions for diets by combining nutritional, costs, ecological and acceptability constraints. LP is an important tool for environmental optimization and shows considerable potential as an instrument for finding solutions to a variety of very complex diet problems.

Healthy diets with reduced environmental impact? - The greenhouse gas emissions of various diets adhering to the Dutch food based dietary guidelines.

OBJECTIVE: To determine the differences in environmental impact and nutrient content of the current Dutch diet and four healthy diets aimed at lowering greenhouse gas (GHG) emissions. METHODS: GHG emissions (as proxy for environmental impact) and nutrient content of the current Dutch diet and four diets adhering to the Dutch food based dietary guidelines (Wheel of Five), were compared in a scenario study. Scenarios included a healthy diet with or without meat, and the same diets in which only foods with relatively low GHG emissions are chosen. For the current diet, data from the Dutch National Food Consumption Survey 2007-2010 were used. GHG emissions (in kg CO2-equivalents) were based on life cycle assessments. Results are reported for men and women aged 19-30years and 31-50years. RESULTS: The effect on GHG emissions of changing the current Dutch diet to a diet according to the Wheel of Five (corresponding with the current diet as close as possible), ranged from -13% for men aged 31-50years to +5% for women aged 19-30years. Replacing meat in this diet and/or consuming only foods with relatively low GHG emissions resulted in average GHG emission reductions varying from 28-46%. In the scenarios in which only foods with relatively low GHG emissions are consumed, fewer dietary reference intakes (DRIs) were met than in the other healthy diet scenarios. However, in all healthy diet scenarios the number of DRIs being met was equal to or higher than that in the current diet. CONCLUSIONS: Diets adhering to food based dietary guidelines did not substantially reduce GHG emissions compared to the current Dutch diet, when these diets stayed as close to the current diet as possible. Omitting meat from these healthy diets or consuming only foods with relatively low associated GHG emissions both resulted in GHG emission reductions of around a third. These findings may be used to expand food based dietary guidelines with information on how to reduce the environmental impact of healthy diets.