Oral nutritional supplements (ONS) are prescribed for paediatric patients living with a disease, disorder or medical condition, and are temporarily, or permanently, unable to meet nutritional requirements through oral diet alone. The most common cause of malnutrition is disease-related malnutrition (DRM), especially in patients that require hospitalisation. The estimated prevalence of DRM in the paediatric population ranges from 5-31% for acute malnutrition and from 12–18% for chronic malnutrition.1 Early detection, management, and/or prevention of malnutrition is advantageous to help optimise nutritional status, growth and development. This article will consider indications for paediatric ONS products, oral nutrition support strategies for children and strategies to increase ONS compliance in this patient group.
Indications for paediatric ONS product
ONS are used for medical purposes and can be prescribed by the NHS for patients who meet the Advisory Committee on Borderline Substances (ACBS) prescribing criteria.2 Children requiring ONS will usually have faltering growth.3 Faltering growth is defined by the National Institute of Health and Care Excellence as a term to describe a slower rate of weight gain in childhood than expected for age and sex. In the UK, this is measured on growth charts which combine the World Health Organisation (WHO) growth standards and UK birth and preterm growth data.4
Children may be unable to meet nutritional requirements through oral diet alone due to increased energy requirements; reduced appetite and/or increased losses or malabsorption. As per the 2023 NICE Clinical Knowledge Summary, risk factors for faltering growth include:
- Feeding problems (such as ineffective sucking, inadequate breast milk and incorrect preparation of infant formula).
- Medical conditions (such as constipation, gastro-oestophageal relfex, coelic disease, diabetes or cleft palate).
- Poor parent/carer-child interactions (including not responding to mealtime cues).
- Poor access to healthy food.
- Family stress, and health problems.
- Child maltreatment.
Dietetic assessment
Before prescribing ONS, a comprehensive nutritional assessment by a paediatric dietitian should be undertaken, considering growth patterns, dietary intake, clinical history and estimated nutritional requirements.
ONS in paediatrics
First-Line Interventions
The National Institute for Health and Care Excellence (NICE) guidelines for faltering growth recommend trialing first-line interventions before ONS. Approaches may include: encouraging relaxed and enjoyable feeding and mealtimes, eating together as a family or with other children, establishing regular eating schedules and avoiding coercive feeding.5
A food-first approach to nutrition support is encouraged in the paediatric population. Fortifying foods increases nutritional density of the diet without increasing the volume of food consumed.
Additional snacks can be used to improve nutritional intake, and encouraging patients to consume nourishing drinks (e.g., smoothies or milkshakes), which provide more energy and protein than water, is also an effective strategy.
Challenges in paediatrics
Picky Eating
There is no universal definition for Picky Eating (PE), but it is widely accepted as a restriction or rejection of familiar foods with or without neophobia.
Ninety-two children aged 36-to-60-months with PE behaviours and evidence of growth faltering demonstrated that ONS, alongside nutrition counselling, over four weeks promoted catch-up growth and reduced incidence of respiratory tract infections.6 If a food-first approach does not work in children with PE, ONS provides an effective way to meet nutritional requirements, while reassuring the caregiver and supporting weight gain (where indicated) in children without other medical conditions.7 More recently, a 2025 meta-analysis8 of five randomised controlled trials involving 874 children confirmed that ONS combined with dietetic consultation significantly improved weight and weight-for-height measures, while also reducing the incidence of upper respiratory tract infections compared with dietetic consultation alone.
Avoidant Restrictive Food Intake Disorder
Avoidant Restrictive Food Intake Disorder (ARFID) is characterised by avoiding eating food or restricting food intake; it does not include having a distorted body image or being preoccupied with body image.9 Children with ARFID may exhibit sensory sensitivity (e.g., avoid specific foods), lack of interest in eating food and/or fear of adverse consequences (e.g., a choking phobia).10 It can have a substantial effect on nutrition and health status and requires a multidisciplinary team (MDT) approach.
An MDT approach is recommended when providing children with oral nutrition support,5 which may include a health visitor, social worker, clinical psychologist, paediatric dietitian and/or occupational therapist. The British Dietetic Association’s (BDA) 2024 position statement on ARFID10 emphasises the unique role of dietitians, noting that “they have expert and up-to-date knowledge and experience of oral nutritional supplements suitable for younger age groups.”
Second-Line Interventions
Oral Nutritional Supplements (ONS)
If a child is unable to meet nutritional requirements through an oral diet alone, the NICE guidelines recommend a trial period of ONS.5 The European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee on Nutrition also recommends ONS should be provided in addition to an oral diet to increase and meet total energy and micronutrient requirements.11 In the UK, these recommendations are reflected in local NHS prescribing policies - for example, the 2025 Norfolk & Waveney Paediatric ONS Prescribing Guidance provides practical criteria for prescribing and review.12 ONS should always be given under medical supervision and used in accordance with care pathways, clinical guidance and ACBS prescribing indications.
ONS Formats
A wide variety of paediatric ONS product formats are available, including ready-to-drink (RTD), dessert-style, juice-style and low volume. More recently, powdered paediatric ONS products have become available. Paediatric ONS generally provide 1.0 kcal/ml to 2.4 kcal/ml in a variety of flavours. ONS products are usually based on cow’s milk protein and age-adapted for energy, protein and micronutrients.
Dosage Considerations
There is a lack of guidance on ONS dosage recommendations in a paediatric population. When considering the ONS dosage, it is important to compare existing oral intake to age and gender-specific nutritional requirements to determine deficit in energy, protein and micronutrients.
In the UK, it is common clinical practice to prescribe sufficient ONS to meet at least 50% of the age-matched reference nutrient intake for micronutrients, while ensuring a balanced mix of essential macronutrients needed for growth. Most children will start with one-to-two ONS per day, depending on their oral intake of solids.
Using Adult ONS Products in Paediatrics
Adult ONS can be used if there are no suitable paediatric products, and the child meets the manufacturer’s recommended age requirements. Some adult ONS can be cheaper than paediatric ONS with a wider variety of flavours and formats (e.g. plant-based) available, which may influence prescribing decisions. Most adult ONS are suitable for children aged over 6-8 years if clinically indicated.13 However, healthcare professionals (HCPs) should always check information with the manufacturer and use their own clinical judgement.
Monitoring progress
Children receiving ONS should be regularly reviewed by a paediatric dietitian to monitor growth and determine whether ONS remains indicated.5
During follow-up appointments, it is important to consider:
- Rapid weight change.
- Linear growth (using the UK-WHO growth chart).
- Changes in dietary intake.
- Tolerance.
- Compliance.
- Knowledge, views, and opinions of the child and/or caregivers.
- Estimated nutritional requirements.
- Changes in clinical status.
If ONS are continued, review acceptability (tolerance/flavour preferences) to ensure they are being taken regularly and as prescribed. If adherence is poor, consider alternative formulations. ONS can also be discontinued when the child is consistently meeting nutritional requirements via the oral diet and growth is on track; for example, the 2025 Norfolk & Waveney Paediatric ONS Prescribing Guidance recommends reviewing ONS at regular intervals and stopping them once oral intake alone meets nutrient needs.12
Compliance
ONS compliance can be defined as the percentage of the prescribed amount of ONS consumed per day;14 compliance optimises growth and reduces waste.16
A 2025 meta-analysis of RCTs involving 1,116 children (mean age 5 yrs) found that ONS led to significantly greater weight gain (+0.4 kg), height gain (+0.3 cm), and exhibited excellent mean compliance (~98%), with a suggestion of reduced infection rates. The authors concluded that ‘this review provides evidence to support use of ONS in the management of children with, or at risk of, faltering growth.'15
Offering powdered-style ONS products made with fresh milk may improve ONS compliance in children and local NHS prescribing guidance recommends considering powdered ONS before ready-to-serve products where appropriate.12 A double-blinded pilot study of 59 participants (including 21 paediatric patients undergoing treatment for cancer) found fresh milk-based supplements were the preferred type of ONS.16
In adult populations, taste fatigue and monotony, which tend to occur when ONS are consumed regularly over prolonged periods, are thought to contribute to poor compliance.17
Therefore, it may be helpful to offer children a variety of flavours and formats. Research has demonstrated that tangible rewards, such as stickers, can increase acceptance of previously disliked foods.18
Conclusion
When used correctly, ONS are useful in children with faltering growth and disease-related malnutrition who are unable to meet nutritional requirements from diet alone. Careful consideration regarding the dosage and format is important to ensure correct product prescription. HCPs should regularly monitor nutritional status, growth and oral nutritional intake to determine whether the prescribed ONS remains indicated. A food-first approach (alongside behaviour strategies) should be encouraged, but if oral intake remains insufficient, ONS can be effective in meeting nutritional requirements.
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Practical considerations for using paediatric ONS
This information was first published on 30 September 2021. It has been updated and reviewed by Cordelia Woodward, Registered Dietitian, of MyNutriWeb in September 2025.