[wlesieutre]

The main point of the article appears to be that the vegan diet doesn't use the perennial cropland. Would be nice if they bothered to mention why. Are the perennial crops 100% feed crops and not something that humans can use, even in crazy reprocessed vegan food substitutes?

[jhardy54]

Reading the actual study, I can't help but think that the authors are being intellectually dishonest. Their logic is thus:

> Cropland in perennial forages included hay crops and grazing on land which could be cropped but is used for pasture.

A: Perennial cropland is used as pasture for animal agriculture.

> Perennial cropland requirements were zero in the vegan diet.

B: Vegans don't require pastures for animal agriculture.

> The ovolacto- and lacto-vegetarian diets used about half of the cropland restricted to perennial forages, while the vegan diet used none of the restricted cropland.

C: Therefore the vegan diet wouldn't have any use for perennial cropland.

This would be true if perennial crops for humans didn't exist, but that's just not true. For example, we can grow perennial sunflower (!), grain (!!) and rice (!!!): https://en.wikipedia.org/wiki/Perennial_crop#Example_crops

[hoggleboggle]

Land is not a problem if vegetables come to reign, hydroponics and aeroponics will easily substitute the inefficient land-use.

Tom et al. (2015) [1] also show that in the US the switch to a vegan diet would be less efficient. But it's natural, from an economic perspective, that existing processes are optimized for efficiency and low costs and given the high demand for vegetables and fruits there would obviously be a huge incentive to optimize the production processes and lower the prices.

Vanham et al. (2013) [2,3] show that EU would benefit from a vegan diet when it comes to water usage.

Overall, it's quite obvious that the medical costs of today are extremely large mostly due to overconsumption of animal products. It is unfortunate that they can be easily overconsumed and thus cause health issues. Diet that includes animals is much more destructive when it comes to dead ocean zones, rainforest destruction, species extinction and water pollution, being the biggest factor in mentioned issues.

[1]: Energy use, blue water footprint, and greenhouse gas emissions for current food consumption patterns and dietary recommendations in the US http://link.springer.com/article/10.1007/s10669-015-9577-y

[2]: The water footprint of the EU for different diets http://temp.waterfootprint.org/Reports/Vanham-Bidoglio-2014....

[3]: Potential water saving through changes in European diets http://www.sciencedirect.com/science/article/pii/S0160412013...

[jahewson]

> Overall, it's quite obvious that the medical costs of today are extremely large mostly due to overconsumption of animal products.

Whoa there, you have no evidence for that claim. The medical impacts of sugar and corn syrup for example have been a disaster. Probably more so than excessive meat. You can't single-out meat, Americans overconsume everything.

[crustygirl]

There's no evidence for sugar and corn syrup that is better than evidence for animal products.

Robert Lustig's bitter truth is a complete lie.

Fact-checking bunch of his "extraordinary" statements, like those about Japanese not consuming fructose, and similar, points that he has an agenda to share.

[hoggleboggle]

why the downvotes? such a welcoming community. I seem to have replied to the wrong parent.

well, I'll leave then :(

[mrob]

It's not at all obvious that the "medical costs of today are extremely large mostly due to overconsumption of animal products". Some people blame sugar, which is made from plants. Some people blame fat, which in the modern American diet is largely vegetable oil. But human nutrition is notoriously difficult to study, so making strong claims about any specific thing being to blame is probably dishonest in some way.

[crustygirl]

USA eats excessive amounts of sugar, fat and calories.

3500kcal per person per day 150kg of meat per person per year (compared to chinese of 60kg, or world average of 40kg).

overconsumption is the word. there was not a hint of criticism of meat being "unhealthy" -- it was mentioned in the frame of overconsumption.

[mrob]

150kg of meat/year is 411g/day. Making the conservative assumption that it's all 20% fat ground beef (in practice it's likely leaner), that's only 1041kcal/day. This is well below the minimum calorie requirement for a healthy adult, so for it to be "overconsumption" there must be something unhealthy about meat specifically.

[crustygirl]

add to that 250kg of milk and 15kg of cheese and you'll soon have no space for any kind of beans, legumes, vegetables and fruits.

as I've said before, problem is overconsumption of everything and animal products take a huge part of that 3500kcal intake.

reducing intake of calorically dense foods is a good step towards battling the rise of killer diseases since most of them are obviously caused by unhealthy lifestyle.

[WalterSear]

This issue puts most people in direct conflict with their own cognitive dissonance: objectivity goes out the window.

[collyw]

Provide some decent evidence. I see plenty of fat unhealthy looking vegetarians.

[WalterSear]

For example - utter non-sequitars like the comment above.

[WalterSear]

It doesn't matter: it's a hit piece. Maximising 'the number of people that can be supported by existing farmland' is not the be all and end all of 'good for humanity'.

[gorhill]

This made me wonder: Maybe returning these lands to their wild state can also be good for humanity when looking at it from another angle than just food production. Something to also consider.

[GFK_of_xmaspast]

I didn't get that either, there certainly are crops grown solely for animal feed, but it's not at all clear why that land can't be repurposed for human-edible crops.

[chris_va]

If I am reading the original paper correctly, there is a bottleneck with the vegan diet that essentially requires you to only use cultivated cropland to get enough of a balanced diet.

The vegan curve never flattens out, because it is entirely dependent on cultivated cropland, unlike the other diets:

https://images.elementascience.org/611000.elementa.f005.PNG_...

[tjl]

Except you can use perennial sunflower which is an oilseed crop for crop rotation.

[chris_va]

I was assuming the bottleneck was protein output, but I cannot find the info in the paper at a glance.