"(...) are contemporary humans suffering from the consequences of chronic, diet-induced low-grade systemic metabolic acidosis?"
A very pertinent article though from almost a decade ago:
In essence, meat is acidifying as is salt, but vegetables can balance the acid. Of course, carbohydrates are also acidifying. No wonder the "traditional" diet based on meat, dairy products, bread, pasta and potatoes would lead to a lot of problems spotted by vegatarians long time ago. Unfortunately vegetarians threw the baby out with bath water and possibly made things even worse with sugars. All was needed was to skip the salt and carbs and eat your greens.
Here are more details:
Also, raw food, including meat, is less acidic than cooked, organ meats are less acidic than muscle meat and some nuts are more acidic than others. It appears that hazelnuts are the best in this respect (and also due to low PUFA content). Keeping all that in mind we can easlily see that a healthy meat and veg eater can be more alakine than a grain and cooked pulses oriented vegetarian.