Meat or meatless meals at lunch and dinner - exploring the associated factors and transition between meals.

This study aimed to explore the factors associated with the consumption of meat vs. meatless meals and to assess the applicability of a multi-state model to describe transitions between lunch and dinner. Fifteen thousand four hundred and eight main meals (lunch and dinner) from a sample of adults (18-84 years, n  = 3852) from the Portuguese Food, Nutrition and Physical Activity Survey (IAN-AF 2015-2016) were categorised as meat, fish, ovolactovegetarian or snack. Adjusted generalised-mixed-effects models were used to explore the associations and a time-homogeneous Markov-multi-state model was applied to study the transitions. Women, older and higher educated individuals presented higher odds of consuming meatless meals and lower hazard of transitioning to meat in the following main meal. Strategies for replacing meat with more sustainable foods should be specific towards different population groups. Studying transitions across main meals, using multi-state models, can support the development of feasible, realistic and group-specific strategies to replace meat and promote dietary variety.