In a recent study published in Scientific Reports, a group of researchers assessed the sustainability of various diets based on protein sources, considering environmental, health, economic, and nutritional aspects. The study used data from a large French cohort.
Study: The nature of protein intake as a discriminating factor of diet sustainability: a multi-criteria approach. Image Credit: Creative Cat Studio/Shutterstock.com
Background
As environmental crises intensify, and efforts to achieve the Paris Agreement's 1.5 °C target fall short, the need to overhaul global food systems becomes critical, given their substantial contribution to Greenhouse Gas (GHG) emissions.
Affluence drives a shift toward calorie-dense, protein-heavy diets, historically fueled by the protein-centric focus dating back to the 1930s and propelled by lucrative animal production markets.
Despite the recognized health risks and high emissions from animal-based foods, Western dietary habits remain largely unchanged, overshadowing the emergent market for plant-based alternatives.
Further research is crucial because current dietary trends, heavily influenced by the evolving "protein" debate and rising meat consumption, are unsustainable in the context of climate goals and public health, necessitating a multi-dimensional analysis, including often-neglected economic factors.
About the study
The present study harnessed data from the NutriNet-Santé cohort, focusing on diets, nutrition, and physical activity's links to health. Participants, all internet-using adults in France, supplied information via regular questionnaires, including lifestyle and dietary habits. The study complies with ethical standards, and participant consent was secured.
Food consumption was analyzed using an Organic Food Frequency Questionnaire (Org-FFQ), encompassing 23 food groups based on protein content. Nutrient values were extracted from a specific food composition table.
Environmental impact was evaluated using the DIALECTE tool and the ReCiPe score, considering factors like greenhouse gas emissions and land use.
Nutritional quality was gauged through three dietary indexes: the Diet Quality Index based on the Probability of Adequate Nutrient Intake (PANDiet), the Programme National Nutrition Santé-Guidelines Score 2 (PNNS-GS2), and the Comprehensive Diet Quality Index (cDQI).
Health risks were assessed via a "Health Risk Score (HRS)," reflecting the death risk related to dietary patterns. Economic data encompassed participants' income and food expenditures.
From the cohort, 29,210 individuals were selected based on data availability and accuracy. The study employed a two-step procedure to identify clusters of individuals with similar protein sources.
These clusters were then examined and compared based on socio-demographic traits, food consumption, and other health and economic indicators.
Statistical analysis utilized Analysis of Covariance (ANCOVA) models for comparisons, with findings indicating variations in food and protein expenditure structures across clusters.
Study results
The study focused on a population primarily composed of women, making up 75%, with an average age of 54 years, revealing intriguing data on protein-source typologies and their implications for health, the environment, and economics.
Analysis of the participants' diets identified five distinct clusters based on their protein consumption patterns. The Milk-based cluster, encompassing 17% of the subjects, preferred milk and beverages like coffee and tea. The Meat-based cluster, representing 26%, primarily consumed more red meat, poultry, and processed meat.
The Fast-food-based cluster, the largest at 29%, leaned towards fast food, cereals, and fatty, sweet products. The Healthy-fish-based and Healthy-plant-based clusters, at 25% and a scant 3%, respectively, favored seafood and plant-derived proteins like soy, legumes, nuts, and fruits and vegetables.
A deep dive into their dietary habits revealed protein intakes ranging from 67 g/d in the plant-based group to 99 g/d in the meat aficionados, with plant-based protein consumption as low as 25 g/d in the meat cluster and as high as 53 g/d in the plant cluster.
Nutritional quality analysis showed the plant-based cluster scoring highest in nutritional quality indices (PNNS-GS2 and PANDiet), reflecting adherence to nutritional guidelines.
In contrast, the fish-based cluster topped the cDQI score, indicating a balance in the quality of animal and plant foods consumed. In contrast, the meat-based cluster scored the lowest, highlighting potential nutritional deficiencies.
From a health risk perspective, the plant-based cluster was the most beneficial, with the lowest HRS, while the meat-based cluster presented the highest risk. It was noted that a diet low in whole grains and legumes and high in red meat significantly contributed to a higher HRS.
Evaluating the environmental impact revealed that the plant-based diet had the least environmental footprint, while the meat-based diet exhibited the most substantial impact.
Interestingly, the consumption of organic foods was most prevalent in the plant-based and healthy-fish-based clusters, with a noticeable decline in the meat-based and milk-based groups.
Economic analysis uncovered that individuals in the healthy-plant-based cluster allocated more of their income to food, often favoring organic products, contributing to higher overall food expenditure. In contrast, those in the meat-based cluster had a lower budget for organic foods.
Regarding protein spending, the meat-based cluster had the highest expenditure, whereas the plant-based cluster spent the least, often focusing on nuts for protein sources.
These findings underscore the diversity in dietary patterns and highlight the interconnectedness of diet with health, environmental, and economic outcomes.
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