Effect of Dietary Supplementation and High-Intensity Motor Learning on Nutritional Status, Body Composition, Muscle Strength, and Motor Skill-Related Physical Fitness in 5-7-Year-Old Children with Moderate Thinness in Ethiopia

Abstract

Background: Despite global efforts, child malnutrition remains a persistent challenge, exacerbating disparities and posing ongoing threats to children and adolescents in developing nations. Malnutrition refers to an inadequate or imbalanced intake of essential nutrients, encompassing both undernutrition and overnutrition. Undernutrition is characterized by an inadequate intake of essential nutrients, resulting in deficiencies. Thinness has been recognized as a more suitable indicator of recent nutritional deprivation, such as insufficient dietary intake of energy, protein, or various micronutrients. Undernutrition is characterized by stunting and thinness. Stunting refers to being short relative to one's age, while underweight is defined in terms of grades of thinness (grades 1–3) and is characterized by rapid weight loss or an inability to gain body mass. Both conditions are linked to poor school attendance and academic performance in mathematics, reading, and writing skills. Additionally, sick or undernourished children often face difficulties with motor function, concentration, problem-solving, and memory recall, all of which contribute to poor academic performance. Undernutrition among schoolchildren in developing countries is a critical global health challenge with far-reaching consequences for their well-being and future opportunities. Nutritional deficiencies during early childhood can lead to poor brain development. Long-term undernutrition can negatively impact academic performance, leading to chronic disorders, hindering cognitive development, and even causing premature death.

Addressing both undernutrition and overnutrition among children aged 5–7 presents a significant challenge for the food and nutrition policies in developing countries like Ethiopia. This age group represents a critical developmental stage marked by key growth and developmental milestones and the development of motor skills. Catch-up growth is particularly important for children with moderate thinness (MT), as they may face developmental delays that could impact their long-term health and well-being. This age is also critical for motor skill interventions as it coincides with significant brain development that is closely linked to cognitive and behavioral growth during preschool years. In Ethiopia, however, MT children aged 5-7 are often overlooked due to the absence of specific treatment guidelines for MT. To address this, the management of acute malnutrition should focus on preventing the progression of MT to severe thinness (ST). To effectively manage MT and prevent its progression to ST, appropriate dietary interventions are essential. This includes providing nutrientrich supplementary food or lipid-based Ready-to-Use Supplementary Food (RUSF) tailored to meet the needs of children with MT. In addition to proper nutrition, motor skill training (high-intensity motor learning (HiML)) interventions significantly enhance motor skill development in typically developing children. HiML is very intensive as it is performed daily over an extended period, requiring a minimum of 30–40 hours of training. The focus is on maximizing time spent on the task during training, with a training/rest ratio of at least 70–30%. Active play, which involves repetitive muscle movements that help build strength, speed, and agility, contributes to the development of both gross and fine motor skills. Furthermore, existing literature on active play or goal-oriented play among preschoolers and early school-aged children demonstrates its positive impact on motor skills. Activities such as ball play, balancing exercises, walking, running, and jumping, or hopping have been shown to improve coordination and physical abilities, reinforcing the importance of integrating both nutrition and physical activity in early childhood development programs. Therefore, the main aim of this study was to evaluate the effect of RUSF with(out) HiML compared to no intervention on various outcomes, including weight, height, body composition, muscle strength, and motor skill-related physical fitness of children with MT age 5-7 living in Jimma, South-West Ethiopia. A summary of each chapter of this dissertation is provided below.