Are meat substitutes providing all the nutrients?

Protein is a nutrient that is essential to the human diet, but there are many options when it comes to protein sources.

Animal protein sources such as chicken, fish, or beef are available. People who do not eat meat may get protein from sources like beans, seeds, and lentils to meet their protein needs.

These plant-based diets may have multiple benefits, including health improvements and being more environmentally friendly.

T​o appeal to this market, producers have worked on developing meat substitutes. These options taste similar to meat, but they come from plant-based sources. Examples of meat substitutes include tofu, tempeh, and seitan.

As certain meat substitutes become more popular, researchers continue to study their benefits and overall nutritional value.

T​his particular study looked at the nutritional value of 44 meat substitutes, looking at components like fiber, fat, protein, and salt content.

They also looked at the bioavailability of the substitutes zinc and iron. Animal products like meat and seafood are good sources of zinc and iron, making it essential to study how meat substitutes compare.

While meat substitutes may contain iron and zinc, the body cannot always use them because of a compound called phytate. Phytate interferes with the body’s ability to absorb iron and zinc and is in many meat substitutes.

Study author Inger-Cecilia Mayer Labba, who is pursuing her doctoral research at Chalmers University of Technology in Sweden explained to Medical News Today that “phytate accumulates during extraction of plant proteins commonly used to produce meat substitutes” and it “has been known for decades to have an inhibiting effect on iron uptake, already at a very low concentration.”

Researchers found wide variations in nutritional value between products. Regarding the nutrient zinc, most meat substitutes did not contain enough of it to be considered an adequate source.

The main exceptions were mycoprotein products, which are derived from fungi. The findings of this study suggest that mycoprotein products may be a good source of zinc.

Still, the study authors note that the “[d]egradability of fungal cell walls might, however, pose as a potential aggravating factor.”

I​n terms of iron, all the meat substitutes studied were not sources of adequate iron. The main exception was tempeh, which came close to “the level of a nutrition claim.”

Mayer Labba noted that the key findings of the study were that:

“Meat substitutes such as sausages, balls, and burgers based on plant protein extracts, which currently is the most common raw material for meat substitutes, have a very low bioavailability of minerals such as iron and zinc. This is due to a very high content of the antinutrient phytate, which is accumulated during protein extraction. Iron is also accumulated during the process, but it is not absorbable due to the high presence of phytate.”

She further explained that: “Fortified iron will be affected in the same negative way as native iron. Even though these kinds of products may have a nutrition claim on iron, it is not in a form available [to] the body, which makes it difficult for consumers.”

The study indicates the need for greater precision in understanding the nutritional value of meat substitutes. It indicates the need for honesty of producers when it comes to the nutrients like iron supposedly found in meat substitutes.

People who want to shift towards plant-based diets can work with their doctors and other nutrition specialists to ensure their diet covers their nutritional needs.

Results of the study indicate that people eating plant-based diets need to consume iron from sources other than meat substitutes.

However, Kristen Carli, a registered dietitian and the owner of Camelback Nutrition & Wellness, questioned some of the findings of this study. She commented to MNT:

“This study implies that ‘meat substitutes’ are not as nutritious as meat. However, one clinical implication that this study overlooks is that people, regardless of diet, do not get all of their nutrition from just meat/ meat substitute sources. Omnivores eat meat but they also eat a variety of other foods containing iron, zinc, and protein. Same goes for vegetarians.”

“It’s possible and even expected that these nutrients would be found in other foods. Additionally, many vegetarians do not eat meat substitutes but instead seek out other forms of plant-based protein, such as beans or quinoa,” she noted.”

“If you are transitioning to a plant-based diet, you do not have to rely so heavily on meat substitutes to provide all of your nutrition needs,” Carli pointed out.