Frequently Asked Questions
How do I get calcium?
From vegetables. More importantly, calcium uptake from the gut is higher when grains and beans are excluded, and calcium losses in the kidneys are expected to be lower as a net result of a Paleolithic diet.
Will protein intake be too high?
Not too high. Protein intake is often high, but not always. In meat, fish and many vegetables, protein is a major energy-providing nutrient (>>Figure>>). In fruit and root vegetables, carbohydrate dominates.
However, it is far from proven that it is harmful with a protein intake around 20–35 E%, i.e. when 20–35 percent of the calories come from protein. Protein is filling and for this reason it prevents overweight. Earlier, a protein intake at 20–35 E% has been suspected of causing osteoporosis (brittle bone), but increasing evidence indicates the opposite. Not even Heaney, whose study from 1982 has been the most cited paper in support of the idea that dietary protein increases bone loss, believes this any more.
Furthermore, the old ’fact’ that high protein diets deteriorate kidney function is being increasingly abandoned. Today, many nephrologists (specialists in kidney disease) say that abdominal obesity and atherosclerosis may have been underestimated as causes of impaired kidney function. If people with diabetes or failing kidneys decrease their waist circumference and improve blood pressure, cholesterol and blood sugar as a result of eating a paleolithic diet, very few doctors would advise them to give up that diet. But they would closely follow up laboratory tests for kidney function.
Is high protein intake beneficial?
Not necessarily. There is insufficient evidence that a protein intake of, say 30 E% (meaning that 30 percent of calories are provided by protein) is more healthy than 20 E%. There are not many studies, and the beneficial effects seen in some of them could be due to other dietary changes, such as restriction of cereals which are the main source of carbohydrate in modern countries. The thought that carbohydrate, in particular starch, is unhealthy is not convincingly backed up by scientific studies >>.
It should also be noted that protein deficiency appears to be rare in western societies, even among vegans. When fruit is the major source of calories protein intake is low, while it is higher when root vegetables are the staple food. Humans are apparently well designed to tolerate highly variable proportions of protein, carbohydrate and fat. In my opinion, these proportions have limited influence on the epidemic of diseases of affluence.
Didn’t these ancestor die at young age?
This is a misunderstanding. Average life expectancy at birth was rather low, but once they reached 50 they may have had a similar chance of living until old age as in modern societies.
Aren’t we adapted to grains and milk?
Not if they cause disease at old age. The time since agriculture emerged is far too short for natural selection to eliminate those who cannot fully handle such food. If you die from atherosclerosis at age 55 or live until 90 does not affect the fitness of your children very much, unfortunately.
Is this some kind of ‘natural’ diet?
Well, the term ‘natural’ is highly problematic. You might say that it is natural to die from mushroom poisoning, that this is the mushroom’s natural way of getting rid of those who try to eat it. Today, sudden cardiac death is natural too. It is wise to avoid the term completely. Nothing is natural.
And more to come...