NETHERLANDS — A Dutch dietary modeling study published in July 2026 found that replacing animal-based proteins with plant-based alternatives on a gram-for-gram basis led to nutrient inadequacies across various age groups. The study, titled 'Shifting to Plant-Based Protein Diets Alters Nutrient Adequacy Across Age Groups: A Dutch Dietary Modeling Study,' appeared in the journal Nutrients.

Researchers used data from the Dutch National Food Consumption Survey (DNFCS), which collected information between 2019 and 2021 from 3,570 participants aged 1 to 79 years. Dietary intake records were gathered through two non-consecutive 24-hour recalls completed over a period of 2 to 6 weeks. The modeling involved two scenarios where meat, poultry, fish, and dairy products were replaced with plant-based alternatives, while mixed dishes and foods with small amounts of animal-derived ingredients remained unchanged.

In both modeled scenarios, total protein intake declined. In the nutritionally conscious scenario, protein intake fell below recommended levels for females in all age groups older than 18 years, and for males aged 31 to 50 and older. In the less nutritionally conscious scenario, females aged 14 to 18 years saw protein intake fall below recommended levels, as did males aged 19 to 30 and older.

The intake of essential amino acids also declined in the modeled scenarios. Combined sulfur amino acid intake (methionine plus cysteine) fell below recommended levels for older adults in both scenarios. Intakes of vitamins A, B1, B2, B3, B6, and B12 generally declined after age 9 in the modeled diets. While folate intake slightly increased for males, meeting recommended daily intake levels, it remained below recommended levels for females.

Calcium intake decreased further in the modeled scenarios, resulting in values below recommended levels for all age groups. Vitamin D intake remained inadequate across all age groups, a pre-existing condition from the original data. Iron intake marginally increased due to greater non-heme iron intake, but it remained insufficient for children and reproductive-aged women. Additionally, intakes of iodine, selenium, and zinc decreased in both modeled scenarios, with zinc intake being inadequate for all age groups after dietary substitution.

Conversely, vitamin E intake increased in the modeled scenarios due to higher concentrations in plant-based foods compared to animal-based foods. Copper intake also increased, while potassium, manganese, and phosphorus intakes largely remained unchanged overall.