Professionally reviewed by Dietitian Chen Zi Xin
As a parent concerned about your child’s health and trying to manage picky eating behaviours, you may have noticed advertisements highlighting nutrients like lysine. Alongside omega-3, commonly known for supporting brain development, these nutrients play important roles in children’s growth and overall wellbeing. Understanding how lysine and omega-3 can benefit children with selective eating or low appetite can help parents make more informed choices to support healthy development.
What is Lysine – The Marketed Solution for Appetite Boosting
You’ve likely heard that eating protein (meat, dairy, egg) is important. That’s because proteins contain amino acids, the building blocks of our body. Lysine is an essential amino acid, which means the body cannot make it on its own and must get it from food. Foods rich in lysine include meat, fish, dairy, eggs, legumes, and soy products. Lysine is important for growth and repair of body tissues, building muscle proteins, immune function, and calcium absorption [1].
More than 60 years ago, a study showed that adding lysine to cereal-based diets improves protein use in children [2]. Since then, lysine has been widely used to fortify foods and as a supplement, especially in regions where diets rely heavily on cereals [3]. Lysine also plays a role in energy production, which is why it is often considered an appetite-boosting nutrient [4].
Even though lysine is naturally present in foods, the amount needed depends on a child’s weight and growth. This raises an important question: what if a child refuses protein-rich foods?
Omega-3 – More Than “Brain Food”
Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can be found in fatty fish (like salmon and mackerel), flaxseed, walnuts, and fortified eggs. They are widely recognized for supporting brain development, learning, memory, and eye health [5,6,7]. For children, omega-3 is essential during growth periods when the brain and eyes are rapidly developing.
Omega-3 is a versatile nutrient that supports healthy growth and long-term wellbeing. Beyond its well-known cognitive benefits, supplementation with EPA, a type of polyunsaturated fatty acid (PUFA) found in fish oil improves appetite, caloric intake, and midupper arm muscle circumference in children undergoing leukemia treatment [8]. While the study focused on children with leukemia, the findings may indicate possible nutritional support for those with poor appetite or feeding challenges.
Children’s growth is complex, and their nutrient needs should be complete, balanced, and sourced from a variety of foods. When managing picky eating behaviours, special attention can be given to lysine and omega-3, as scientific studies have highlighted their benefits. Supplementation may be considered when it is challenging to provide these nutrients through food alone, or when specific amounts are required under the guidance of a healthcare professional. Now that we’ve explored what these nutrients are, the next step is to understand how they can support growth, appetite, and overall wellbeing. (The Science Behind Appetite and Behavior: How Lysine and Omega-3 Work Together)
About the Reviewer
Chen Zi Xin is a registered dietitian with the Malaysian Dietitians’ Association (MDA) and a member of the Malaysian Allied Health Professional Council (MAHPC). With experience in nutraceuticals and healthcare marketing, she contributes to product development and professional nutrition training, including hospital nurse and pharmacist programs. She is driven by the belief that informed nutrition transforms daily health outcomes.
References:
- Singh, M., Rao, D. M., Pande, S., Battu, S., Mahalakshmi, K., Rajeswar Dutt, K., & Ramesh, M. (2011). Medicinal uses of Lysine: Past and future. International Journal of Research in Pharmaceutical Sciences, 2(4), 637–642.
- Bressani, R., Wilson, D., Behar, M., Chung, M., & Scrimshaw, N. S. (1963). Supplementation of cereal proteins with amino acids. IV. Lysine supplementation of wheat flour fed to young children at different levels of protein intake in the presence and absence of other amino acids. Journal of Nutrition, 79(3), 333–339.
- Gunarathne, R., Guan, X., Feng, T., Zhao, Y., & Lu, J. (2025). L-lysine dietary supplementation for childhood and adolescent growth: Promises and precautions. Journal of Advanced Research, 70, 571–586.
- GlobinMed. (n.d.). Lysine (78227). Retrieved March 16, 2025, from https://globinmed.com/medicinal_products/lysine-78227/
- Rombaldi Bernardi, J., de Souza Escobar, R., Ferreira, C. F., & Pelufo Silveira, P. (2012). Fetal and neonatal levels of omega3: Effects on neurodevelopment, nutrition, and growth. The Scientific World Journal, 2012, 202473. https://doi.org/10.1100/2012/202473
- BeluskaTurkan, K., Korczak, R., Hartell, B., Moskal, K., Maukonen, J., Alexander, D. E., Salem, N., Harkness, L., Ayad, W., Szaro, J., Zhang, K., & Siriwardhana, N. (2019). Nutritional gaps and supplementation in the first 1000 days. Nutrients, 11(12), 2891. https://doi.org/10.3390/nu11122891
- Sass, L., Bjarnadóttir, E., Stokholm, J., et al. (2021). Fish oil supplementation in pregnancy and neurodevelopment in childhood: A randomized clinical trial. Child Development, 92(4), 1624–1635. https://doi.org/10.1111/cdev.13541
- Abu Zaid, Z., Shahar, S., Jamal, A. R., & Mohd Yusof, N. A. (2012). Fish oil supplementation is beneficial on caloric intake, appetite and mid upper arm muscle circumference in children with leukaemia. Asia Pacific journal of clinical nutrition, 21(4), 502–510.
