Been interested in Peat´s diet for a year and a half now, and also incorporated many of his principles and ideas into my diet.
A lot of confusion remains, however, such as the acid/base balance and various other issues I will describe below. I am sorry if this appears to be an unnecessary long rant.
First of all, I don´t know if Peat at all acknowledges the so called "potential renal acid load" (PRAL), but if he does, it kind of upsets the idea of the all importance of the calcium to phosphate ratio.
The PRAL formula is as follows:
protein +0.49
phosphorus +0.037
potassium -0.021
magnesium -0.026
calcium -0.013
So for example, it would take almost three mg´s of calcium to balance one mg of phosphorus.
This is not an issue with cow milk where the high protein is balanced with ample amounts of potassium so it is only slightly overall "acidic". It is a major problem with cheese which is almost completely absent in potassium. Human milk has very little phosphate and about 2:1 calcium:phosphate, but it is also very low in protein, so it is very alkaline compared to cow milk (according to this formula).
Another issue to consider I think is that as the result of the cholesterol hysteria, we have been eating much less organ meats and egg yolks the past 50 or so years. Additionally while dairy product intake may have been relatively constant, so that we probably similar amount of calcium from dairy products, we now eat far more hard cheeses and much less milk.
The issue with lack of organ meats and egg yolks and the increase in muscle meats is very important because the composition of the two types of animal foods are very different. One major difference is that organ meats is sometimes exceptionally high in choline and selenium, and other nutrients like pantothenic acid and B12. 100 gram of beef brains provide as much as 450 mg of choline (4 egg yolks) and 100 grams of beef kidneys can provide 200 mcg of selenium, compared to perhaps 70 mg and 15 mcg respectively for typical muscle meats.
100 gram swiss (hard) cheese may provide 16 mg choline, 18 mcg selenium and 0.4 mg pantohenic acid, while 1 quart of milk may provide 140 mg choline, 36 mcg selenium and 3.5 mg pantothenic acid.
Choline/lecithin should help the body burn fat for energy (like liver fat), while selenium perhaps will help boost thyroid function. Pantothenic acid also appears to be useful in weight loss by helping to turn fats and carbohydrates into energy.
A third issue I find of interest is that potassium is not allowed to be sold in higher amounts than 99 mg (2% of the RDA) over the counter, and is not so often prescribed by doctors. Potassium could potentially have added a lot of alkaline matter to the diet and thus perhaps prevent or cure many diseases like diabetes.
The sippy diet at one point popular (very alkaline) seems also be discouraged as a cause of heart attacks, and in just recent years calcium has also started to be banned.
Smoking, a very stimulating substances that works almost as a weight loss (or preventation of weight gain) agent for many people, has been increasingly "banned" the past decades.
Going through this it almost seems as some sort of big conspiracy where the goal is to make us as fat as possible, or perhaps a "conspiracy" from big pharma where the substances that make their most profitable drugs become obsolete, has somehow been removed from us via fear propaganda, or just by indirect prohibition (for example by only allowing doctors to prescribe potassium). The annual worldwide cost of diabetes from drugs and reduced productivity could be as high as $1 trillion annually, of which perhaps half end in the pockets of big pharma. Yet there´s been several smaller "paleo type" studies suggesting it could be reversed in a matter of months. Already 30 years ago O´Dea published a study where australian aboriginal people reversed diabetes in just 6 weeks by changing to their original environment, but there´s been very little follow up of such remarkable studies, not even the later one´s performed in Sweden by Staffan Lindeberg et al.
I was looking at some of Staffan Lindeberg´s few studies comparing a paleo diet with a so called "mediterranean" diet. The problem is that the "mediterranean diet" is not really a mediterranean diet as people in these countries do not use whole grains, while all the "mediterranean diets" in research use whole grains, sometimes very large quantities. Whole grains of course is very rich in phosphate and cause the acidic overall load of the diet.
In one of the studies the paleo group ate 1500 calories while the control group ("mediterranean diet") ate about 1800 calories. There was no "restriction" on calories for the paleo diet meaning caloric intake was spontaneously reduced. My thinking is that it was reduced partially because metabolism was increased due to a more alkaline diet (a total PRAL of about 0 verus +15 for the control diet).
The other study was more extreme, where the paleo group only ate 1350 calories, while the control group ate 1800 calories. In this case, however the difference in potential renal acid load appears to be much bigger as the control group ate about 50% more dairy and whole grains. This means more calcium, however. Diabetes was more or less reversed in 3 months in the paleo group, but in the "mediterranean diet" the improvement in glucose tolerance was very minor.
One of the mechanisms is described by Peat I believe in that a higher calcium to to phosphate ratio reduces parathyroid hormone, which leads to weight loss (and increased metabolism), "milk drinkers is usually slim" he says. (But what about cheese eaters?) In these paleo diets phosphate is lower (no whole grains and dairy), and is perhaps more easily removed via higher content of potassium. However I also believe the calcium to phosphate balance in the body will be higher as more calcium is "spared" as other components like potassium is used instead to balance out excess phosphate.
So one possible hypothesis based on all this is that Peat is not "wrong" per se, he himself suggest that the alkaline minerals can displace each other. But it does suggest that a blind focus on the calcium to phosphate ratio can be very troublesome and sometimes irrelevant, in this case a person may think it´s fine to just eat 100 grams of cheese instead of a quart of milk. My main point is that cheese should be used with caution, and avoided unless the diet incorporates more organ meats/egg yolks and more fruits and vegetables.
A final point is that Peat´s suggestion of 2 quarts of milk plus 1 quart of orange juice, a few eggs and 1 or 2 raw carrots, for weight loss is in many ways "perfect" in this sense as it has the choline, a very alkaline overall ash, plus plenty of important nutrients etc. I would esimate such a diet is probably more or less exactly as alkaline as human milk (2000 kcal worth of human milk has a PRAL of about -15, vs +15 for cow milk).
A lot of confusion remains, however, such as the acid/base balance and various other issues I will describe below. I am sorry if this appears to be an unnecessary long rant.
First of all, I don´t know if Peat at all acknowledges the so called "potential renal acid load" (PRAL), but if he does, it kind of upsets the idea of the all importance of the calcium to phosphate ratio.
The PRAL formula is as follows:
protein +0.49
phosphorus +0.037
potassium -0.021
magnesium -0.026
calcium -0.013
So for example, it would take almost three mg´s of calcium to balance one mg of phosphorus.
This is not an issue with cow milk where the high protein is balanced with ample amounts of potassium so it is only slightly overall "acidic". It is a major problem with cheese which is almost completely absent in potassium. Human milk has very little phosphate and about 2:1 calcium:phosphate, but it is also very low in protein, so it is very alkaline compared to cow milk (according to this formula).
Another issue to consider I think is that as the result of the cholesterol hysteria, we have been eating much less organ meats and egg yolks the past 50 or so years. Additionally while dairy product intake may have been relatively constant, so that we probably similar amount of calcium from dairy products, we now eat far more hard cheeses and much less milk.
The issue with lack of organ meats and egg yolks and the increase in muscle meats is very important because the composition of the two types of animal foods are very different. One major difference is that organ meats is sometimes exceptionally high in choline and selenium, and other nutrients like pantothenic acid and B12. 100 gram of beef brains provide as much as 450 mg of choline (4 egg yolks) and 100 grams of beef kidneys can provide 200 mcg of selenium, compared to perhaps 70 mg and 15 mcg respectively for typical muscle meats.
100 gram swiss (hard) cheese may provide 16 mg choline, 18 mcg selenium and 0.4 mg pantohenic acid, while 1 quart of milk may provide 140 mg choline, 36 mcg selenium and 3.5 mg pantothenic acid.
Choline/lecithin should help the body burn fat for energy (like liver fat), while selenium perhaps will help boost thyroid function. Pantothenic acid also appears to be useful in weight loss by helping to turn fats and carbohydrates into energy.
A third issue I find of interest is that potassium is not allowed to be sold in higher amounts than 99 mg (2% of the RDA) over the counter, and is not so often prescribed by doctors. Potassium could potentially have added a lot of alkaline matter to the diet and thus perhaps prevent or cure many diseases like diabetes.
The sippy diet at one point popular (very alkaline) seems also be discouraged as a cause of heart attacks, and in just recent years calcium has also started to be banned.
Smoking, a very stimulating substances that works almost as a weight loss (or preventation of weight gain) agent for many people, has been increasingly "banned" the past decades.
Going through this it almost seems as some sort of big conspiracy where the goal is to make us as fat as possible, or perhaps a "conspiracy" from big pharma where the substances that make their most profitable drugs become obsolete, has somehow been removed from us via fear propaganda, or just by indirect prohibition (for example by only allowing doctors to prescribe potassium). The annual worldwide cost of diabetes from drugs and reduced productivity could be as high as $1 trillion annually, of which perhaps half end in the pockets of big pharma. Yet there´s been several smaller "paleo type" studies suggesting it could be reversed in a matter of months. Already 30 years ago O´Dea published a study where australian aboriginal people reversed diabetes in just 6 weeks by changing to their original environment, but there´s been very little follow up of such remarkable studies, not even the later one´s performed in Sweden by Staffan Lindeberg et al.
I was looking at some of Staffan Lindeberg´s few studies comparing a paleo diet with a so called "mediterranean" diet. The problem is that the "mediterranean diet" is not really a mediterranean diet as people in these countries do not use whole grains, while all the "mediterranean diets" in research use whole grains, sometimes very large quantities. Whole grains of course is very rich in phosphate and cause the acidic overall load of the diet.
In one of the studies the paleo group ate 1500 calories while the control group ("mediterranean diet") ate about 1800 calories. There was no "restriction" on calories for the paleo diet meaning caloric intake was spontaneously reduced. My thinking is that it was reduced partially because metabolism was increased due to a more alkaline diet (a total PRAL of about 0 verus +15 for the control diet).
The other study was more extreme, where the paleo group only ate 1350 calories, while the control group ate 1800 calories. In this case, however the difference in potential renal acid load appears to be much bigger as the control group ate about 50% more dairy and whole grains. This means more calcium, however. Diabetes was more or less reversed in 3 months in the paleo group, but in the "mediterranean diet" the improvement in glucose tolerance was very minor.
One of the mechanisms is described by Peat I believe in that a higher calcium to to phosphate ratio reduces parathyroid hormone, which leads to weight loss (and increased metabolism), "milk drinkers is usually slim" he says. (But what about cheese eaters?) In these paleo diets phosphate is lower (no whole grains and dairy), and is perhaps more easily removed via higher content of potassium. However I also believe the calcium to phosphate balance in the body will be higher as more calcium is "spared" as other components like potassium is used instead to balance out excess phosphate.
So one possible hypothesis based on all this is that Peat is not "wrong" per se, he himself suggest that the alkaline minerals can displace each other. But it does suggest that a blind focus on the calcium to phosphate ratio can be very troublesome and sometimes irrelevant, in this case a person may think it´s fine to just eat 100 grams of cheese instead of a quart of milk. My main point is that cheese should be used with caution, and avoided unless the diet incorporates more organ meats/egg yolks and more fruits and vegetables.
A final point is that Peat´s suggestion of 2 quarts of milk plus 1 quart of orange juice, a few eggs and 1 or 2 raw carrots, for weight loss is in many ways "perfect" in this sense as it has the choline, a very alkaline overall ash, plus plenty of important nutrients etc. I would esimate such a diet is probably more or less exactly as alkaline as human milk (2000 kcal worth of human milk has a PRAL of about -15, vs +15 for cow milk).