Going from meat to vegetarian or vegan diets may result in a surprising and troubling change in the types of foods people choose to add to their diets. In a study published in The Journal of Nutrition, researchers divided more than 21,000 adults into four groups—meat eaters, pesco-vegetarians (whose diet includes fish), vegetarians and vegans—and analyzed daily food intake.

The study found that those who followed vegetarian and vegan diets appeared to consume more ultraprocessed foods (UPFs). These are packaged foods like potato chips, ice cream, and the new wave of engineered meat and dairy substitutes, like foods made from textured soy protein and plant-based drinks made from soy, almond or rice. Those who initiated a meat-free diet at a younger age were more likely to include more UPFs in their diet.

Those who believe that steering clear of meat and dairy is enough to improve health should also check out a separate investigation, published in the International Journal of Behavioral Nutrition and Physical Activity. Using 13 years of data from nearly 92,000 people, this study found that those with the highest likelihood of cardiovascular-related death in that time frame were more likely to eat the most UPFs.

The takeaway here is that people pondering a plant-based lifestyle need to be educated on how to meet their nutrition needs using predominantly whole-food options.

See also: Bone Up on Vegan Nutrition