Plant-based nutritional pitfalls: Why novel products don’t necessarily improve diet quality - Study
Globally, there is a boost in new plant-based meat alternatives that are being marketed as sustainable and good for health.
Novel plant-based meat alternatives are highly formulated, processed products that rely on protein isolates, colours, flavours and processing aids to achieve a “meat-like” sensory appeal.
However, there is no evidence on long-term consumption of substituting animal-based foods for newer plant-based meat, dairy and eggs.
Much more is known about the health benefits of omitting meat in favour of traditional plant sources such as legumes, with evidence demonstrating lowered risks of cardiovascular disease, diabetes, cancer and obesity for vegetarians and vegans.
“An additional concern is the current focus on promoting plant-based foods of “unhealthy” product categories and formats such as plant-based burgers, nuggets, meatballs and sausages, which may increase consumption of so-called junk foods,” according to scientists in Singapore and the Netherlands.
For this study, researchers selected a reference omnivore diet based on the average nutrient intake pattern for an American adult male aged 20 to 49, using NHANES 2017–2018 data.
They modelled traditional and novel versions of flexitarian, vegetarian and vegan diets and compared them to the reference diet.
Novel diets were those that included plant-based protein alternatives while traditional diets comprised mainly of traditional plant-based foods such as pulses, legumes and vegetables.
They found that diets comprising novel plant-based substitutes fell below daily requirements for most micronutrients.
Traditional flexitarian and vegetarian diets were the only two diets to meet daily micronutrient requirements.
Researchers said food producers should seize this opportunity to create the next generation of plant-based foods that provide adequate nutrient intake and sensory appeal without the addition of salt, sugar and fat, yet in an innovative format that attracts consumers.
The findings were published in the journal Nutrients.
In this study, flexitarian diets was defined as reduced intake of meat and dairy, and more plant-based foods.
The traditional flexitarian diet was lower in saturated fat and sodium and higher in calcium and magnesium than the reference diet, due to the higher proportion of low-fat dairy and plant-based foods such as legumes.
The novel flexitarian diet had less vitamin B12, zinc and potassium, and higher saturated fat and sodium than the reference diet.
“This was due to a greater proportion of novel plant-based convenience foods such as plant-based snacks, coconut-based products and lower dairy intake,” researchers said.
The traditional vegetarian diet was lower in saturated fat and sodium and higher in calcium and magnesium than the reference diet, due to the increased intake of dairy and plant-based products such as vegetables, beans, tofu and nuts.
The novel vegetarian diet with its higher intake of plant-based meat alternatives and coconut-based snack products, was lower in vitamin B12, zinc, potassium and calcium compared to the reference diet. This diet also exceeded the reference diet for saturated fat and sodium.
The vegan diet excluded all meat and dairy, and mostly comprised of legumes and seeds, so had zero cholesterol.
Traditional vegan diet was the diet with the highest iron and fibre, and higher in potassium and magnesium compared to the reference diet. However, it also had lesser vitamin B12 and calcium. Soy milk is the sole source of vitamin B12 for vegan diets.
The novel vegan diet was lacking in vitamin B12, calcium, potassium, magnesium and zinc, compared to the reference diet, although it provided sufficient phosphorus and iron.
“Since many novel plant-based meat alternatives were rich in iron due to the inclusion of vegetable haem or ferrous sulfate, the novel vegan diet had one of the highest overall iron contents,” researchers explained.
The novel vegan diet was also higher than the reference diet for saturated fat and sodium and had the lowest fibre of all the diets due to the greatest proportion of plant-based meat alternatives and plant-based snack foods.
This study demonstrates that plant-based diets with larger proportions of novel plant-based meat alternatives and vegan diets run the risk of being inadequate in many important micronutrients, and that flexitarian diets seem to be the most feasible in transitioning to a healthier and sustainable diet.
In particular, researchers cautioned against consumers making the switch to plant-based diets, especially vegan diets which had low intakes of calcium and zinc.
“A diet with sustained low calcium content can increase the risk of low bone mineral density, osteoporosis and fractures.”
Several foods catered to vegans such as falafel and halloumi, which are commonly fried, and non-dairy alternatives such as vegan cheese, yogurt and ice cream, tend to be lower in protein and micronutrients when compared to animal-based dairy products.
In addition, non-dairy milks targeted towards vegetarians or vegans are often high in added sugar, and many vegetarian and vegan spreads, snacks and desserts have high levels of salt and fat.
Recent innovation in the plant-based product space has focused more on organoleptic properties (texture, taste and appearance) and formats (nuggets and burgers), rather enhancing the nutrient density of plant-derived foods, and ensuring a balanced nutrient profile similar to products of animal origin.
Researchers say there are opportunities for novel plant-based meat alternatives manufacturers to develop affordable, sustainable, and nutritious meat and dairy analogues to enhance the nutritional content of diets and benefit consumer health.
“Rather than attempting to construct foods replicating meat or dairy, it may be more nutritious and feasible to encourage consumers to reduce meat and increase consumption of existing nutrient-dense, natural plant sources,
“Investments and marketing could focus on promoting intakes of fresh vegetables, legumes and seeds rich in protein instead of plant-based meat alternatives products, which are not equivalent nutritionally and are more costly for consumers,
“Improving the availability of fruits and vegetables in schools, workplaces and communities coupled with choice architecture and strategies to increase palatability of such foods have shown promise.”
“Unintended Consequences: Nutritional Impact and Potential Pitfalls of Switching from Animal- to Plant-Based Foods”
Authors: Rachel Tso and Ciarán G. Forde