Paleo and keto diets bad for health and the planet, says study

Paleo and keto diets bad for health and the planet, says study
Eating a meat-forward diet is likely not good for human or planetary health, says the new study
Eating a meat-forward diet is likely not good for human or planetary health, says the new study
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Eating a meat-forward diet is likely not good for human or planetary health, says the new study
Eating a meat-forward diet is likely not good for human or planetary health, says the new study

The health benefits of a meat-based versus a plant-based diet are often hotly debated both in the research community and by self-styled health gurus on social media platforms. A new study adds another checkmark to the plant-based column, this time looping in the environmental impact from choosing the paleo or keto diets over veganism. The findings, the researchers hope, could help people choose diets that are not only nutritious, but environmentally friendly as well.

When it comes to the more extreme ways of eating, the paleo and keto diets are on one side of the field, while veganism is on the other. Paleo dieters focus on meats, vegetables, fruits and nuts while avoiding beans and grains, while Keto practitioners dial back nearly all carbohydrates, focussing instead on meats and fats. Vegans avoid all animal products and animal byproducts in their diet.

While it's possible to find studies touting some benefits and some drawbacks on human health from both ways of eating, researchers out of Tulane University took a slightly different approach to comparing the eating plans: they tracked how much carbon dioxide paleo and keto diets release into the atmosphere versus a plant-based diet. Carbon dioxide is a key contributor to global warming trends, so understanding how it gets into the atmosphere can help mitigation efforts.

To compile their results, the researchers used information from a database they had previously developed called dataField, which tracks the carbon footprint of various foods. They also examined the nutritional impacts of the various types of diets by applying point values derived from the federal Healthy Eating Index to data from over 16,000 adults participating in the CDC's National Health and Nutrition Examination Study.

They found that for every 1,000 calories consumed, the keto diet generates nearly 3 kg of carbon dioxide, while the paleo diet releases 2.6 kg of the greenhouse gas into the atmosphere. Vegans, on the other hand, only release 0.7 kg of carbon dioxide for each 1,000 calories they consume, meaning that paleo and keto diets create nearly four times the greenhouse gas emissions as vegan diets. In the middle of the field, omnivores–who made up 86% of those in the study released 2.2 kg of carbon dioxide per 1,000 calories.

The researchers say their findings indicate that if only a third of omnivores switched to a vegetarian diet, the environmental impact would be akin to removing the carbon output of 340 million passenger vehicle miles on any given day.

Healthwise, the study gave the highest marks to pescatarian diets, which release 1.66 kg of carbon dioxide into the atmosphere per 1,000 calories consumed, so it forms a kind of compromise between nutritional quality and carbon emissions. Vegan and vegetarian diets followed close behind in terms of having high nutritional content, while keto and paleo diets lagged.

“Climate change is arguably one of the most pressing problems of our time, and a lot of people are interested in moving to a plant-based diet,” said study senior author Diego Rose. “Based on our results, that would reduce your footprint and be generally healthy. Our research also shows there’s a way to improve your health and footprint without giving up meat entirely.”

The study has been published in The American Journal of Clinical Nutrition.

Source: Tulane University

David F
A paleo diet adds more CO2 to the atmosphere than a vegan diet, but plants need CO2. Whereas a vegan diet consumes more CO2 from the air, the very gas plants need, yet veganism is better for the environment. Such doublethink is an inevitable consequence of predicating the health of the environment on the flawed premise that CO2 is harmful.
LOL, eat bugs, own nothing, and you WILL like it.
I'm just glad I'm old enough I won't have to put up with this nonsense much longer.
That is if the world doesn't nuke itself in a year or less.
Same as Mediterranean diet. They are healthy because they are walk up and down hills for entre life, not because they eat tomatoes. Driving everywhere and eating tomatoe once in a while cannot have same effect. Paleo? How about moving as much as people were moving back then? Besides it is not even similar diet. When animal was available it was not only pretty muscles that were eaten. Everything eatable would got eaten. But today's paleo dieters are too soft for that.
What a joke. I would love to meet the authors of this “study” to find out what their eating habits are. Did you ever notice how low carb eating always gets the bad press while vegan and vegetarian diets are always shown in a positive light? That said, here we have another “study” written by authors that didn’t actually go and do any work in the field. Looks like they just mined for the data they needed. How about this: let people figure out what works for them?
Lamar Havard
All plants have their own kind of poison in them that they produce to keep from being eaten before they can RE-produce. And carbohydrates are the main cause of inflammation in the body. The carnivore diet is the best for overall health.
Keto/paleo diets are *not* simply "eating meat". They reflect the diet humans evolved their entire metabolism to utilise over tens of thousands of years and therefore are diets which logically make most sense for us to follow to maintain health (when combined with sensible exercise regime) - not necessarily to the nth degree, though. Fish would (for most humans living near the sea or large bodies of water, generally) would also play as much a part in a normal diet - just as it should today.

Meanwhile, Kellogg (et al) have been around for barely a century - and their extremely effective advertising borders on the criminally fraudulent (not to mention being the absolute worst demonstration of corporate greed and cynicism in the history of business).
Here is the link at which you find how the study authors define the various kinds of diets. https://doi.org/10.1016/j.ajcnut.2023.01.009 They did it by what was not in the diets, not by what the subjects actually ate. The canard is in the assumption that keto eaters are massive meat eaters; they aren't. They know that excessive protein, whether from animals or plants, is bad, for them just as people with CKD know that it slowly destroys kidneys. If fossil fuel keeps warming and acidifying the oceans, that food chain will fail, as will land-based food production as weather patterns change.
Jean H
Great comments! Regenerative farming with grass-fed ruminants as a necessary component deserves a place in media headlines. It would be nice if New Atlas writers reached out to successful regenerative farming operations that are healing the land while feeding healthy red-meat eaters.
Quite a range of comments - but a few very insightful ones! So great article Michael as you managed to get many people talking.
David F: I'm glad you can focus on the CO2 levels in the atmosphere. Did you know CO2 levels have a "Goldilocks" range with mammals? Further, do you know plants have developed very slick ways of capturing minute levels of CO2 for photosynthesis? Do you know the current levels and continued rise in CO2 levels are endangering those plant processes that have allowed them to survive for tens of thousands of years? Do you know at what level the CO2 concentration will begin to induce narcosis in humans, and reduce photosynthesis in plants? If not, then don't even consider calling the premise of rising CO2 either flawed or not harmful. Some things just need to be said.
Karmudjun: thank you. David F: more is never always better, let's take O2 for example. O2 is required for humans to live. Add way more O2 into the air, and it's absolutely toxic - every single one of us would die. As for C02 -- the bulk of the extra is absorbed by the ocean .... which turns acidic, and, at a very-soon-to-be point: all sea life dies. So more C02 = bad.
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