The protein transition into context – the impact of dietary shifts in different countries on nutritional adequacy of diets

The term ‘protein transition’ is used to address a dietary shift from animal-source foods (ASF) to plant-source foods (PSF). This indirectly implies a focus on protein as the main nutrient of concern to reduce food-related pressures on the environment and tackle unhealthy diets. In a Western context, there is growing consensus that a protein transition is indeed favorable but it can be misinterpreted as a uniform solution, and specificity for low- and middle-income countries (LMIC) are lacking. This study examined the nutritional implications of replacing currently consumed ASF with PSF to achieve diets that align with the protein transition, for low-, middle- and high-income countries. Using data from dietary surveys as a starting point, we stepwise replaced currently consumed ASF with currently consumed PSF to either meet current energy intake, or current total protein intake. The results show that substituting ASF either increased the nutrient adequacy gaps for eight out of nine studied nutrients when maintaining current energy intake, or largely increased energy intake when maintaining current total protein intake. More importantly, nutrient adequacy of current and alternative diets showed large variability among countries, age- and gender groups, while culturally specific (animal-source) foods were an important source of nutrients. There is no uniform solution for sustainable healthy diets, and rather research in this area should consider nutritional needs of the target population and culture specific food habits. • The protein transition cannot be applied as a uniform, global solution • High diversity of food consumption requires a wide range of dietary transitions • Protein is not the main, and certainly not the only, nutrient of concern • Food transitions should shift from being protein oriented toward nutrient-density oriented