Protein-energy malnutrition (PEM) is a growing concern on account of an aging population and its negative health consequences. While dietary protein plays a key role in the prevention of PEM, it also plays a pivotal role in the environmental impact of the human diet. In search for sustainable dietary strategies to increase protein intake in older adults, this study investigated the readiness of older adults to accept the consumption of the following alternative, more sustainable protein sources: plant-based protein, insects, single-cell protein, and in vitro meat. Using ordinal logistic regression modeling, the associations of different food-related attitudes and behavior and sociodemographics with older adults’ acceptance to consume such protein sources were assessed. Results were obtained through a consumer survey among 1825 community-dwelling older adults aged 65 years or above in five EU countries (United Kingdom, the Netherlands, Poland, Spain, and Finland). Dairy-based protein was generally the most accepted protein source in food products (75% of the respondents found its consumption acceptable or very acceptable). Plant-based protein was the most accepted alternative, more sustainable protein source (58%) followed by single-cell protein (20%), insect-based protein (9%), and in vitro meat-based protein (6%). We found that food fussiness is a barrier to acceptance, whereas green eating behavior and higher educational attainment are facilitators to older adults’ acceptance to eat protein from alternative, more sustainable sources. Health, sensory appeal, and price as food choice motives, as well as gender and country of residence were found to influence acceptance, although not consistently across all the protein sources. Findings suggest that there is a window of opportunity to increase older adults’ acceptance of alternative, more sustainable protein sources and in turn increase protein intake in an environmentally sustainable way in EU older adults.

Food waste generated at the household level represents about half of the total food waste in high-income countries, making consumers a target for food waste reduction strategies. To successfully reduce consumer food waste, it is necessary to have an understanding of factors influencing food waste behaviors (FWB). The objective of this study was to investigate socio-demographic predictors of FWB among consumers in two European countries: Denmark and Spain. Based on a survey involving 1518 Danish and 1511 Spanish consumers, we examined the associations of age, sex, education, marital status, employment status, and household size with FWB. By using structural equation modeling based on confirmatory factor analysis, we created the variable FWB from self-reported food waste and two activities that have been correlated with the amount of food wasted in previous studies: namely, shopping routines and food preparation. Results show that being older, unemployed, and working part-time were associated with less food waste behavior in both countries. In Denmark, being male was associated with more food waste behavior, and living in a household with four or more people was associated with less food waste behavior. These results underscore the modest role of socio-demographic characteristics in predicting food waste behavior in Europe.

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

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.