Analysis of 19 Approved Preterm/Low Birth Weight Infant Formulas for Special Medical Purposes

As of now, China has officially approved 19 preterm/low birth weight infant formulas for special medical purposes. The food team at CIRS Group will provide a detailed analysis of the energy density, macronutrient energy supply ratio, and ingredient sources of these products.

Approval status

The 19 products consist of 11 domestic formulas and 8 imported ones from 14 companies. Among these, Abbott has had three formulas approved, while Nestlé, Yili, and Feihe each have had two. Of the 19 products, 17 are powdered products and two are liquid. All the domestic formulas are powders.

Table 1 19 approved preterm/low birth weight infant formulas for special medical purposes

Formula characteristics

According to the Recommendations on Feeding Preterm/Low Birth Weight Infants by the Neonatology Group of the Chinese Medical Association’s Pediatrics Society, preterm/low birth weight infants are defined as newborns with a gestational age of less than 37 weeks and a birth weight of less than 2,500 g. These infants differ significantly from full-term infants in terms of physiological conditions, nutritional needs, and ability to digest and absorb nutrients. To support their catch-up growth, the levels of energy, protein, and certain vitamins and minerals in their formula are significantly higher than those in formulas designed for full-term infants.

Table 2 Energy density and energy supply ratios of nutrients

1) Energy density

According to GB 25596 and its related guidelines, the energy content of preterm and low birth weight infant formulas should be within 250 kJ to 465 kJ per 100 mL, as specified in Standard 4.4, which is equivalent to 0.6 kcal to 1.1 kcal per mL. As shown in the table, the energy density of the 19 approved formulas ranges from 0.68 kcal/mL to 1.00 kcal/mL, with most products centered around 0.8 kcal/mL.

2) Protein

Protein intake is essential for the optimal growth and development of preterm infants. Randomized controlled trials have demonstrated that insufficient protein intake can lead to long-term consequences, including potential cognitive decline. *

* Reference: ESPGHAN Committee on Nutrition. Enteral nutrient supply for preterm infants: commentary from the European Society of Paediatric Gastroenterology, Hepatology and Nutrition Committee on Nutrition. J Pediatr Gastroenterol Nutr. 2010 Jan;50(1):85-91.

According to GB 25596 and its guidelines, the protein content in such formulas should not fall below the minimum value specified in Standard 4.4, while the upper limit can be adjusted as necessary. This approach aligns with the recommendations from the European Society of Paediatric Gastroenterology, Hepatology and Nutrition’s guidelines on enteral nutrition for preterm and low birth weight infants, which emphasize that while exceeding the required protein intake shows no adverse effects, inadequate protein intake can hinder growth.

The protein content in such formulas ranges from 0.45 g to 0.98 g per 100 kJ, which is equivalent to a protein energy ratio of 7.7% to 16.7%. As shown in Table 2, the 19 approved formulas have a protein energy ratio ranging from 11% to 13%. This represents an appropriate increase compared to the protein energy ratios of other infant formulas for special medical purposes, which range from 7.7% to 11.9%.

GB 25596 does not specify particular types of protein sources, but due to the specific needs of the target population, formulas generally prioritize high-quality milk proteins. Among the 19 approved products, the primary protein sources are predominantly a combination of whey protein powder and milk powder, with some also incorporating casein or hydrolyzed milk protein. Notably, demineralized whey powder and skim milk powder are the most commonly used ingredients.

Table 3 Ingredient sources of protein

3) Fat

The AAP (American Academy of Pediatrics) research report recommends that such formulas should provide approximately 40% of their energy from fat to ensure sufficient total energy intake to support growth and optimize the utilization of dietary protein.

According to GB 25596 and its guidelines, the fat content in such formulas should range from 1.05 g to 1.90 g per 100 kJ, which is equivalent to a fat energy ratio of 38.6% to 70.3%. As shown in Table 2, the fat energy ratio in the 19 approved formulas ranges from 45% to 49%, with most products centered around 46%. Only two products have a fat energy ratio of 49%.

GB 25596 stipulates that such formulas should include easily digestible medium-chain fats as part of the fat source, with medium-chain fats comprising no more than 40% of the total fat content. Among the 19 approved products, the fat sources are primarily a combination of medium-chain triglycerides (MCTs), which enhance fat absorption, and various vegetable oils. A few products also include palm (kernel) oil, (low erucic acid) rapeseed oil, and 1,3-dioleic acid-2-palmitic acid triglyceride. Sunflower oil and soybean oil are the most commonly used vegetable oils, both offering a high absorption rate of up to 96% and being rich in linoleic acid, an essential fatty acid. MCTs are preferred because they are absorbed more rapidly in the intestines compared to long-chain triglycerides (LCTs), serving as an immediate energy source.

Table 4 Ingredient sources of fat

4) Carbohydrates

Carbohydrates are the primary source of energy. The AAP research report recommends that approximately 50% of the energy in infant formulas should come from carbohydrates, typically derived from lactose or nutritionally equivalent disaccharides, oligosaccharides, or polysaccharides. GB 25596 and its guidelines state that in preterm and low birth weight infant formulas with increased energy content, the higher fat content may reduce the carbohydrate content. As a result, there is no minimum limit required for carbohydrates in these formulas.

According to GB 25596, the carbohydrate content should range from 2.2 g to 3.3 g per 100 kJ, which corresponds to an energy ratio of 37.4% to 56.1%. Among the 19 approved products, the carbohydrate energy ratio ranges from 37% to 43%. For formulas with a higher fat-energy ratio, the carbohydrate energy ratio is appropriately reduced.

It is stipulated in GB 25596 that, except for specific cases such as lactose intolerance, the preferred carbohydrates should be lactose and/or glucose polymers. Only pre-gelatinized starch is permitted in infant formulas for special medical purposes, while fructose is not allowed. Among the approved products, carbohydrates primarily derive from lactose, maltodextrin, and glucose syrup.

Table 5 Ingredient sources of carbohydrates

According to GB 25596 and its guidelines, the upper limits for energy, protein, and certain vitamins and minerals in formulas for preterm and low birth weight infants can be adjusted based on practical considerations. The above information represents CIRS Group's statistical analysis of energy density, macronutrient energy ratios, and ingredient sources, aimed at supporting companies in their formula development efforts.

For more information about the registration of FSMP in China, please click here to learn about our FSMP registration service.

If you need any assistance or have any questions, please get in touch with us via service@cirs-group.com.