Is the LCHF diet suitable and safe for infants?

Marlene Ellmer, BSc Diet, M Nutr, RD (SA,UK)

From a nutritional perspective, pregnancy, breastfeeding and infancy are a critical and vulnerable time period. The nutritional requirements are very different at this stage, from the average healthy adult and as a result it should not be assumed that LCHF diets are safe and suitable.

Maternal nutritional excesses and deficiencies during pregnancy are associated with increased risk of non-communicable diseases (NCDs) such as T2DM, hypertension and heart disease. Faster infant weight gain in the first 2 years of life is also associated with higher NCD occurrence in adulthood. The first 1,000 days of life i.e. from conception until 2 years, is a very vulnerable period for programming of NCD risk and as such is a key target stage for prevention of adult disease¹. 

Those of you who attended the Extraordinary People talk would have heard Prof. Tim Noakes state that “breast milk contains 52% saturated fat” and as a result, saturated fat must be good for us. He also took reverence to the “high carbohydrate diets from baby jars” that children are being weaned onto and that are largely contributing to childhood obesity. He has recently advised not only to wean infants onto LCHF but that breastfeeding mothers must also follow a LCHF diet.

The nutrition misinformation being disseminated to this vulnerable group is of concern and it is therefore imperative to explore the available scientific evidence.

Breast milk composition

It is well known that breast milk varies in composition from mother to mother, is affected by stages of lactation (colostrum vs. transitional milk vs. mature milk), by gestation and age of the baby, time of day, mother’s nutritional status, population, environment, as well as according to expression and management of breast milk i.e. storage.^2,3 Therefore, it can never be said that all breast milk has “x” amount of macronutrients, but the literature does give the following analysis of human milk composition based on numerous human milk samples*:

*The gold standard of milk collection involves sampling of all milk expressed over 24 hours, with collection on multiple occasions from the same individuals over time.

**NA = information not available

It is clearly indicative above, that if it is argued that infants should be weaned onto a diet similar to breast milk, they should be weaned moderate fat, moderate carbohydrate and low protein diet. However, more on this later.

Contrary to popular belief, the mother’s dietary macronutrient composition does not entirely dictate the macronutrient composition of her breast milk. Literature shows that the nutritional components of human milk derive from 3 sources: synthesis in the breast cells, dietary origin and from maternal body stores.² This may explain why severely malnourished mothers of low socio-economic status, can ensure adequate infant growth with their breast milk. Generally, the nutritional quality of human milk is preserved, but attention to maternal diet is still imperative for some vitamins and the fatty acid composition of the milk.² Of particular significance is omega-3 and -6 fatty acids which are essential for infant brain development.²

Studies indicate that the maternal gut may be the origin of certain bacteria found in the umbilical cord blood, amniotic fluid and in human milk. Oligosaccharides in the mother’s diet, may stimulating the growth and activity of beneficial bifidobacteria and lactobacilli in the infant, thus improving immune health.⁷ More studies are needed in this area to make definitive conclusions but it is important to note that these vital oligosaccharides are found in vegetables, legumes and whole-grains.

The following are well established factors affecting the macronutrient composition of human milk²:

• The mother’s body mass index (BMI)
• Protein and essentially fatty acid intake
• Nursing frequency
• Quantity of the breast milk produced (the higher the volume of milk produced the higher the carbohydrate content)

Fat is the most variable macronutrient in breast milk samples. It is thought, according to small studies, to be affected by a variety of factors including the mother’s protein intake.² The quantity of long-chain polyunsaturated fatty acids (omega-3 and -6) in the mother’s diet is replicated in her breast milk. Therefore, for a favourable breast milk fatty acid profile, it is strongly recommended that mothers eat a diet rich in omega-3 fatty acids or that they take a suitable supplement.

Nutritional requirements for an infant of weaning age

The World Health Organisation (WHO)³ recommends that infants should be exclusively breastfed until the age of 6 months, at which point their nutritional requirements change and appropriate complementary food is necessary. Estimates of nutrient requirements for non-breastfed infants for the first 6 months life, are based on measured intakes of human milk.

From 6-12 months the WHO and other bodies^3,7,8 recommend the following nutrient intakes to ensure growth and nutritional adequacy:

Energy⁷:                                                                646- 742 calories per day

Protein (Safe levels) ⁸                         1.14 – 1.31g/kg/day or 6 – 7% of TE

Fat³:                                                       30 – 45% of TE

Prof. Tim Noakes has not stated his position on the correct macronutrient % distribution of LCHF weaning diets for infants, nor has he provided scientific evidence to support his recent statements. It must be reiterated therefore, that reducing the carbohydrate intake in infant’s diets with no short-term or long-term evidence is strongly ill-advised.

Implications of LCHF weaning diets

A LCHF weaning diet is the steady increase in dietary protein intake, predominantly animal proteins, as the infant increases in age. Although it is well known that iron found in animal products is an extremely important mineral in the weaning diet, excessive intake of animal products, saturated fat and protein is not recommended for this vulnerable group. Strong evidence is now emerging that high protein intake in the first 2 years of life is linked to obesity and health risks later in child- and adulthood.¹⁰ Recent systematic reviews showed a relationship between high-protein intake, a higher BMI and increased risk of later onset obesity as well as other NCDs.^10,11,12 This has actually prompted several infant feeding companies to drop the protein content in their infant formula products prescribed for 6 months and older.

Another implication is the risk of vitamin, mineral and trace-element imbalance LCHF diets may pose, and their detrimental effect on the mother and infant’s nutritional status. Furthermore, the effects of ketosis as a result of a low carbohydrate diet, is highly questionable and potentially dangerous for infants unless strictly monitored by a paediatrician specialising in metabolic illnesses. When a ketogenic diet is initiated for specific medical nutrition therapy in children under the age of 1 year, this child will be admitted to hospital for strict observation.

We are all in agreement that salt, sugar and refined carbohydrates are not recommended for the weaning diet and foods high in these ingredients should be limited wherever possible. However, despite recommendations to give balanced home-made meals, baby jars can offer convenience in extenuating circumstances and are both suitable and safe to use on these occasions. It is unwarranted to label “all jarred foods” as are high in sugar and carbohydrates. Instead the focus should be to educate mothers in reading of food labels and selecting of food choices carefully.

The ideal and safe weaning diet for children should contain a variety of vegetables, fruit, potato, sweet potato, rice, oats, eggs, pasta, chicken, meat, pulses, oily fish, white fish, good quality whole-grains and dairy products such as yoghurt and cheese. This should be given from 6 months of age in addition to breast milk or infant formula. From 12 months of age, fresh pasteurised cow’s milk can be introduced and full fat dairy products are recommended until the age of 2 years.

If you are in doubt about your child’s diet contact a Dietitian in your area who has a specific interest in paediatric nutrition.