The Planetary Health Diet: Why Cutting Meat and Dairy Risks Human Health

Planetary Diet
Written By Aida Krgin

In 2019, the EAT-Lancet Commission introduced what they called the “Planetary Health Diet.” It was promoted as a way to feed 10 billion people by 2050 while protecting the planet. The idea sounded noble: shift global diets toward more plants, less meat and dairy, and align human health with environmental sustainability.

The diet quickly gained traction. Governments, policymakers, and institutions pointed to it as a blueprint for the future of food. It was praised as the solution to climate change, chronic disease, and food insecurity all at once.

But what happens when you actually put it to the test?

A recent clinical trial gave us a look. For 12 weeks, participants followed the Planetary Health Diet. The outcome was not glowing. Essential nutrients dropped across the board:

  • Retinol (vitamin A): down 25%

  • Thiamin: down 11%

  • Riboflavin: down 16%

  • Niacin: down 16%

  • Calcium: down 16%

  • Zinc: down 13%

  • Potassium: down 10%

  • Selenium: down 15%

  • Iodine: down 26%

  • Vitamin B6: down 12%

  • Vitamin B12: down 36%

  • Vitamin C: down 23%

  • Vitamin D: down 28%

  • Vitamin K1: down 30%

These are not fringe vitamins and minerals. They are the very nutrients that allow our bodies to function properly. B12 is essential for neurological health and red blood cell production. Vitamin D supports immunity and bone health. Retinol, the active form of vitamin A, is critical for vision, reproduction, and growth. The list goes on.

In only 12 weeks, these numbers reveal how fragile human nutrition becomes when meat and dairy are stripped away.

Planetary Health Diet (EAT-Lancet Diet)

The Planetary Health Diet is not fully vegan, but it allows only very small amounts of animal foods. Daily targets look like this:

  • Red meat: 14 g (about one bite)

  • Poultry: 29 g

  • Fish: 28 g

  • Eggs: 13 g (about 1 egg per week)

  • Dairy: 250 g (about 1 glass of milk per day)

The bulk of the diet is built on whole grains, legumes, fruits, vegetables, nuts, and seeds. It was designed around environmental sustainability models, not purely around human nutritional needs.

This distinction matters. While it does not ban animal foods, the allowed quantities are so low that they struggle to meet human nutrient requirements without fortification or supplementation.

Nina Teicholz’s Pushback

Nina Teicholz, author and nutrition researcher, has been one of the most outspoken critics of the Planetary Health Diet. Her message is blunt but necessary: human health should not be sacrificed to meet an environmental agenda.

She points out that the recent clinical trial shows what happens when people follow this diet in the real world. Within 12 weeks, nutrient levels dropped sharply, not by a fraction, but by double digits across vitamins and minerals that are essential for life. To her, this is not a minor issue of fine-tuning. It is a clear signal that the diet, as designed, is not compatible with long-term human health.

Teicholz also highlights the way the EAT-Lancet report was built. It was not developed from decades of clinical data or lived human dietary practices, but from mathematical models and projections. Experts sitting in boardrooms decided what the “ideal” diet should look like, balancing spreadsheets of emissions and land use. But food is not eaten on paper. It is eaten by people, with complex biological needs.

Critics, including Teicholz, argue that the report reflects more ideology than nutrition science. It was shaped by policy goals and a push to meet climate targets, not by evidence of what nourishes the human body. That is why she warns against adopting it as a global standard. To do so would be to ignore the evidence from biology in favor of a political narrative.

Her broader concern is that once diets like this are codified into policy, they will be promoted as “healthy” regardless of the consequences. If nutrient deficiencies show up, they will be downplayed or dismissed. History has already shown how dietary guidelines can get entrenched and resistant to change, even when the science doesn’t support them. The low-fat movement of the late 20th century is a perfect example. For decades, fat was demonized, processed foods were promoted as “heart healthy,” and rates of obesity and chronic disease continued to rise. The risk, Teicholz argues, is that the Planetary Health Diet could repeat the same mistake on a global scale.

The real issue, she stresses, is whether we are willing to let ideology override biology. If the diet leads to widespread deficiencies, the outcome will not be health but chronic illness. And that is not sustainability.

The Hidden Tradeoff

The narrative being pushed is that we must eat less meat and dairy to save the planet. But the numbers suggest the cost is high: widespread deficiencies in the very nutrients that keep people alive and healthy.

Will policymakers and institutions present this diet as “healthy” while minimizing or hiding the deficiencies? That’s a real concern. Public health guidelines have a history of promoting simplified messages that ignore unintended consequences.

Why Are Alternatives Ignored?

There are ways to produce food that both nourish humans and support the environment. Regenerative farming, rotational grazing, and mixed farming systems restore soil, support biodiversity, and can even sequester carbon. Livestock can play a positive role when managed responsibly.

Meanwhile, large-scale monocropping of soy, wheat, and corn—the backbone of plant-based diets—depletes soil nutrients, requires chemical fertilizers and pesticides, and drives ecological damage. It makes little sense to call this “sustainable” when it harms both the land and human nutrition.

What Are the Numbers Really Telling Us?

The numbers are clear: removing nutrient-dense animal foods leads to nutrient decline. A 36% drop in B12 and a 28% drop in vitamin D in only three months is not sustainable. Imagine what happens over years or decades.

This should make us pause. Do we want to live on a planet where humans are chronically undernourished, fatigued, and sick, all in the name of sustainability?

If human health collapses, how is that sustainable?

The Bigger Question

We need to ask why this narrative is being pushed so strongly. Why are we told the only solution is to reduce animal foods? Why is soil-depleting, chemical-dependent plant agriculture painted as “the answer”?

The story does not add up. It oversimplifies a complex issue, ignores promising solutions, and risks long-term harm to human health.

A truly sustainable food system must nourish humans first. Without health, there is no future worth protecting.

References

Disclaimer: The content shared here is for informational and educational purposes only and should never be taken as medical advice.

In writing this blog post, my goal is to distill research findings into a clear, approachable format that encourages critical thinking and empowers you to make informed decisions about your health.

Aida Krgin
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