Ingredients Matter: Carbohydrates and Infant Formula

As a part of our Ingredients Matter series, we asked Registered Dietician Amy Powderham to tell us about the role carbohydrates play in the diet of infants… Background: What are carbohydrates? Carbohydrates are one of the three main nutrients (the others being fat and protein) that humans require in large quantities in their diet. As well as providing the body’s principal source of energy, carbohydrates have other important applications such as energy storage and the formation of DNA. Carbohydrates are so named because their molecular structure consists of carbon, hydrogen, and oxygen. They are a group of molecules for which the digestible component is the sugar monomer, monosaccharide. Monosaccharides are carbohydrate ‘building blocks’ and are found in glucose, fructose and galactose. In chemistry, carbohydrates are classified according to factors such as their degree of polymerisation and linkage. In nutrition, for the purposes of distinguishing how they behave in our digestive systems and impact our health, the sub-categories used are typically digestible and non-digestible carbohydrates. Digestible carbohydrates are digested and absorbed by the small intestine whilst non-digestible carbohydrates are resistant to this and travel to the large intestine. You may find that the latter are more commonly referred to as ‘dietary fibre’. Fibre is fermented by gut bacteria, creating by-products that can be used as energy for the body, and is associated with health benefits such as increasing stool bulk, decreasing intestinal transit time and lowering total cholesterol and LDL-cholesterol¹. Put simply, this means dietary fibre is a beneficial nutrient to include in the diet Other familiar terms are ‘complex’ and ‘simple’ carbohydrates. Complex carbohydrates are those consisting of many sugar molecules bound together, requiring extensive digestive breakdown before the body can absorb them. These complex carbs are found in starchy foods like bread, potatoes, and pasta, which can contain both digestible and non-digestible carbohydrates. Simple carbohydrates are the sugars monosaccharides and disaccharides, which are far easier for the body to absorb. Complex carbohydrates can be processed or refined so that they require a less lengthy digestive breakdown before absorption, which is done by removing the non-digestible components. For example, by removing the outer layer, or ‘bran’, of the wheat grain the starch granules within the grain are more accessible to the digestive enzymes. This speeds up how quickly the starch is broken down to its monosaccharide components that can enter the blood. A further consequence of removing the fibrous content from the carbohydrate when processing some foods may be that the micronutrients i.e., the vitamins and minerals housed there are also lost. Because this is true of milled flour, in the UK it is required by law to fortify non-wholemeal flour with thiamine, niacin, calcium and iron. More recently, the government have also mandated the addition of folic acid. Owing to carbohydrates being the principal source of energy in our diets, infant formula must consist of an adequate amount of carbohydrates to achieve an acceptable nutritional profile. What is the source of carbohydrate in infant formula? EU regulations dictate that infant formula must consist of 9-14g per 100kcal of carbohydrates, and that only specific carbohydrates, in specific quantities, can be used.² This equates to roughly 35-50% of total energy provided by infant formula coming from carbohydrate, specifically the carbohydrates lactose, maltose, sucrose, glucose, glucose syrup (or dried glucose syrup), maltodextrins, pre-cooked starch and gelatinised starch. Sucrose and glucose may only be added where the formula is manufactured from protein hydrolysates i.e., extensively or partially hydrolysed rather than whole cows’ or goats’ milk protein, and there are maximum limits on how much sucrose, glucose, glucose syrup (or dried glucose syrup), pre-cooked starch and gelatinised starch can be used. Lactose is the natural carbohydrate found in breastmilk and is also the preferred carbohydrate source in infant formula³. Lactose provides important benefits for infants when compared to other carbohydrate sources such as glucose and maltodextrin.

Beneficial effects on gut physiology include, prebiotic effects, softening of stools, effective absorption of water, calcium and sodium⁴

For infant formula there is a minimum requirement (EU) on the inclusion of lactose at 4.5g/100cal^2. The only exceptions to this being where a formula is labelled ‘lactose free’, in compliance with these regulations, or where soya protein isolates make up more than 50% of protein content. Summary Carbohydrates are important macronutrients that provide the energy your body needs to function properly. Regulations dictate the amount and type of carbohydrates in infant formula to ensure that infants receive the energy and nutrition they need. This includes minimal requirements on the inclusion of lactose, unless a formula is predominantly soya protein based or 'lactose free', owing to it being the sugar found in breast milk. Interest lies in the contribution of digestible verses non-digestible carbohydrates in the diet when it comes to our health, particularly owing to increasing evidence to suggest non-digestible, dietary fibre is beneficial to our health. Most children and adults are achieving recommended intakes of 50% total energy from carbohydrates, but limited numbers of all age groups meet free sugar limitation and fibre intake recommendations.

by Amy Powderham

Registered Dietician

amypowderham.com

Want to read more on lactose and intolerance? Take a look at 'Understanding infant feeding disorders and their misconceptions

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References

1. Scientific Advisory Committee on Nutrition (SACN). Carbohydrates and Health. 2015; Available from: https://www.gov.uk/government/publications/sacn-carbohydrates-and-health-report
2. Commission TE. COMMISSION DELEGATED REGULATION (EU) 2016/ 127 - of 25 September 2015 - supplementing Regulation (EU) No 609/ 2013 of the European Parliament and of the Council as regards the specific compositional and information require. Off J Eur Union [Internet]. 2016;L25(609). Available from: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32016R0127&from=EN%0Afile:///C:/Users/miche/Documents/Citavi 6/Projects/Milk_Lokal_210918/Citavi Attachments/Office - COMMISSION DELEGATED REGULATION EU 2016 (2).pdf Y3 - 21.12.2020 S1 - 29 M
3. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN)
4. Koletzko B, Baker S, Cleghorn G, Neto UF, Gopalan S, Hernell O, Hock QS, Jirapinyo P, Lonnerdal B, Pencharz P, Pzyrembel H, Ramirez-Mayans J, Shamir R, Turck D, Yamashiro Y, Zong-Yi D. Global standard for the composition of infant formula: recommendations of an ESPGHAN coordinated international expert group. J Pediatr Gastroenterol Nutr. 2005 Nov;41(5):584-99. doi: 10.1097/01.mpg.0000187817.38836.42. PMID: 16254515.