About 94 per cent of New Zealanders still eat meat, according to 2018 data from more than 47,000 people.
The study also found that 86 per cent ate an unrestricted meat-based diet, while just under 6 per cent were vegetarian or vegan.
Researchers at the University of Waikato, University of Auckland and Victoria University of Wellington conducted the study.
They said concerns over potential negative effects of excessive meat consumption on both the environment and personal health, coupled with long-standing debates over animal rights, have motivated research on the prevalence and predictors of plant-based versus meat-based diets.
However, few studies had examined longitudinal trends in dietary behaviours using large national samples, researchers said.
They addressed this gap by examining the prevalence, predictors, and annual change in the self-reported dietary behaviour of a large national probability sample of New Zealand adults, (categorised as omnivore, vegetarian, or vegan).
Consistent with researchers' pre-registered hypotheses, omnivore was the most prevalent dietary category (94.1 per cent).
Moreover, they found higher levels of conservative ideologies (such as political conservatism, Right-Wing Authoritarianism, and Social Dominance Orientation), lower disgust sensitivity, and lower subjective health predicted having an omnivore (vs. vegetarian or vegan) diet.
Longitudinal analyses further revealed that the probability of shifting from an omnivore diet to a vegetarian or vegan diet over a one-year period was low, and that veganism was the least stable dietary category.
Researchers also found that both gender (men) and political conservatism predicted lower probabilities of transitioning from meat to no-meat diets over time.
Given that meat-eating was so widespread, and over-consumption had health and environmental consequences, researchers said the focus may need to be on cutting back on meat - rather than cutting it out altogether.
Find out more about the study here.