Autoimmune Thyroid Disease

An Unfortunate and Lengthy Adventure in Misdiagnosis

Optimal diet ratios and human breast milk

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Optimal diet macronutrients ratios are P : F : C = 1 : 3 : 0.8. In one of his books Dr Jan Kwasniewski makes a bizarre comment about how the Optimal Diet ratios match human breast milk and are therefore the ideal ratios for human adults. This has been refuted by numerous somewhat mocking sources who point out that the ratios for human breast milk are quite different to the Optimal Diet ratios.

Everyone has a different ratio for the amount of fat in breast milk. They appear to vary widely between people: the Weston A. Price Foundation quote the stats:

P : F : C = 1 : 9.2 : 6.5

This translates as 4% protein, 82.8% fat, 26% carbohydrate. That’s certainly an optimal amount of fat!

I don’t think Dr K got the message across very well, or perhaps the translation fell down a bit. He talks about the lactose part of the milk as being a “body building” component.

Lactose is composed of glucose and galactose. Galactose is actually an essential sugar that is not used for energy but goes towards building myelin to protect nerves and neurons. This is 13% of the energy in the baby’s diet, leaving 13% as glucose for fuel.

WAPF say: “Human milk contains higher levels of lactose than that of other mammals because of higher requirements for galactose in the development of the more advanced human nervous system and brain.”

Galactose is clearly something that babies need in large quantities, but that adults only need in small quantities.

On top of this, babies have very large brains in comparison with their body size. The brain is one of the few organs that requires glucose, in fact it runs largely on glucose given the choice, so a baby’s glucose need is proportionately higher than an adult’s.

According to this site, a baby’s brain is 13% of its body weight, but by the time the child is a teenager, this has fallen to about 3%, and will fall to 2% as an adult.

This page, says the brain consumes 10x more energy weight for weight than the rest of the body, or 20% of total energy.

If the brain ran solely on glucose, it would consume 100-125 grams of glucose per day in an adult, which is about right because below 100 grams ketones begin to rise significantly in the blood order to fuel the brain. Fortunately the brain runs more efficiently on ketones than glucose!

A growing baby needs around 49 calories per pound of body weight, so a 7 pound baby would need about 350 calories per day. 45.5 kcal of this would come from glucose.

If we were dealing with adult proportions, 20% of total energy (the proportion used by the brain) would equal 70 kcals.

A baby’s brain is 13% of its weight instead of 2%, but only 13% of the baby’s energy comes from glucose compared to the 20% an adult would use if the adults’s brain ran on glucose. It is surprising that the baby does not need more glucose. Either the baby’s brain does not consume disproportionately more energy than its body (it must not, or it would need 130% of its energy to come from glucose!), or the brain is running at least partially on galactose and/or ketones.

In other words, the ratios differ for babies, but they’re still optimal for its size and shape. Its increased need for carbohydrates comes from its disproportionately large brain.


Written by alienrobotgirl

12 April, 2006 at 3:53 pm

2 Responses

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  1. I saw this post on the AHOA forum and looked into similar sources and I agree with you. It absolutely makes sense. Not only that, but consider the amount of growing a baby needs to do during the time when they are typically nursing (the first 1 to 3 years of life where they literally double or triple in size) and how much energy that would require, compared to an adult, who isn’t growing at all. I’m surprised they don’t require more glucose, as well. Love those ketones!

    Mother Nuture

    12 April, 2006 at 4:26 pm

  2. A book I came across recently that seems very interesting is: Survival of the Fattest: The Key to Human Brain Evolution. by Stephen C. Cunnane. (”The book describes us as the only land mammal with fat-babies and why this ‘fatness’ gave us an advantage in the (brain) nutrition department.”Also interesting I found to be: “Human babies are biologically extremely immature when they are born. Nils Bergman points out that the newborn’s brain size is only 25% of its final size, which he compares with 45% in chimpanzees and 80% in antelopes. Not until around one year of age does the human baby’s brain reach 80% of its final size. Compared with other mammals, we should have a 21-month pregnancy. The reason human babies are born so early and so immature is the fact that the width of the birth canal through the mother’s pelvis was reduced when our ancestors started walking upright. At the same time the brain volume increased. The evolutionary solution was that babies began to be born earlier and therefore more immature, and in need of constant parental care.” (source: Kangaroo Mother Care: An Interview with Dr Nils Bergman —, 21 months, that would bring us very close to the 22 months pregnancies of elephants.)


    3 October, 2007 at 3:46 pm

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