Nutritional Status and Dietary Behaviors of Children with Intellectual or Developmental Disabilities in Saudi Arabia: A Systematic Review

Introduction

Worldwide, more than 290 million children are disabled.¹ A disability could contribute to the development of malnutrition through several pathways.² Malnutrition and disability interplay in various manners. Disability-associated feeding difficulties, nutritional inadequate absorption, and social isolation are a few forms in which disability might raise the likelihood of malnutrition.³ In comparison to children without disabilities, those with disabilities had a three-fold increased risk of malnutrition.⁴ Furthermore, children with disability are more likely to experience detrimental consequences from malnutrition, including higher mortality rates.⁵

The risk of malnutrition can be increased among disabled children due to several factors, such as long-term restrictive diets, the existence of medical comorbidities, hyperactivity, unhealthy feeding patterns, and family dietary behaviors.⁶ Undernutrition can have a substantial negative influence on the health status and quality of these children.⁷ Moreover, children with disabilities may be more susceptible to becoming overweight or obese, which can be linked to side effects from psychiatric medications, sleep issues, the home environment, challenges with motor skills, physical inactivity, sedentary lifestyle, diet selection, and a craving for high-energy foods.⁸ On the other hand, they are at higher risk of nutritional deficiencies such as deficiency of several vitamins and minerals, which could negatively affect their growth and development.⁹

Prenatal and neonatal diet quality could be the root cause of many childhood disabilities by impacting epigenetic inheritance.¹⁰ Increasing rates of disability are associated with the neonatal diet and the prenatal consumption of ultra-processed foods and nutritional deficits.¹⁰ The processes used in the production of many food ingredients result in the widespread presence of heavy metal residues in the food system. Children who consume food loaded with heavy metal residues could build up lead and mercury in their blood and have signs of disabilities such as autism.¹¹ Furthermore, exposure to heavy metal residues during pregnancy may affect a child’s gene function and cause intellectual or developmental impairments.¹² If families do not improve their diets, disability prevalence will continue to rise.¹³

In Saudi Arabia, the disability prevalence in 2016 was estimated at 3.3% of the population (about 0.7 million out of 20 million), which is lower than the global disability rate (15%).¹⁴ Moreover, the disability rate among Saudi children aged 19 years or younger was 2.7% (about 0.2 million out of 7.8 million).¹⁴ The general healthcare system and the disability care services in Saudi Arabia have been progressively developed in terms of facilities and professional staff during the last few decades.¹⁵ The governmental and private sectors are being promoted to invest more in consumer access to healthcare.¹⁵ Healthcare facilities are establishing human rights committees to oversee the rights of individuals with disabilities.¹⁶ Scientific research on disability has steadily increased in Saudi Arabia.¹⁷ However, many challenges are faced in Saudi Arabia regarding the public health and disability sector. To effectively integrate individuals with disabilities into the community, a more efficient healthcare system that provides equitable treatment, patient rights insurance, and financial support for families with limited resources is required.¹⁵ Furthermore, governmental bodies should spend additional funds on disability management. Hospitals and healthcare facilities should upgrade their infrastructure and qualified staff to deliver high-quality healthcare for disabled patients.^18,19 It is important to monitor the implementation of national policies and programs that are designed to integrate disabled patients with the public health system and community.¹⁵

The current study aims to review the research findings related to the nutritional status and dietary behaviors of children with intellectual or developmental disabilities (IDD) in Saudi Arabia. This systematic review is noteworthy because it offers a thorough summary of the data that is currently available regarding the nutritional status and dietary behaviors of children with IDD in Saudi Arabia. In addition, methodological issues and research gaps were emphasized, which can aid in boosting the quality of subsequent studies from Saudi Arabia in this field. The current study is founded on the following assumptions. First, a limited number of studies examined the nutritional status and dietary behaviors of children with IDD in Saudi Arabia. Second, these studies commonly assessed only specific aspects of nutritional status and dietary behaviors. Third, the outcomes of these studies were highly variable.

Methods

In the current review, IDD are disorders that typically manifest from birth and have an adverse effect on an individual’s physical, intellectual, and/or emotional development pathway. The IDD cases included in this review are autism spectrum disorder (ASD), Down syndrome (DS), attention deficit hyperactivity disorder (ADHD), and cerebral palsy (CP). Throughout the review, the PRISMA guidelines were adhered to.²⁰ The study protocol was registered on the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY). The registration number is INPLASY202420055.

Research Questions Identifying

The current study was carried out to find answers to several questions. First, what are the findings that can be collected from available literature related to nutritional status among children with IDD from Saudi Arabia? Second, what are the findings of available literature related to dietary behaviors among children with IDD from Saudi Arabia? Finally, what are the research gaps and methodological issues that can be emphasized in the available literature to help improve future research?

Literature Search Strategy

The literature search was handled by two authors to locate appropriate research articles that had been published up to December 2023 in Web of Science, Scopus, PubMed, and Google Scholar databases. Used keywords were grouped into four types of terms: target population terms (children, child, adolescents, teens, teenagers, youth, boys, girls, and toddlers), IDD terms (intellectual disabilities, developmental disabilities, intellectual disability, developmental disability, Down syndrome, attention deficit hyperactivity disorder, ADHD, autism spectrum disorders, ASD, autism, autistic, and cerebral palsy), nutritional status and dietary behavior terms (nutritional status, nutrition, malnutrition, weight, body mass index, BMI, diet, dietary behaviors, food, feeding behavior, eating, and meals), and geographic location terms (Saudi Arabia, Saudi, Kingdom of Saudi Arabia, KSA, Riyadh, Jeddah, Mecca, Medina, and Dammam). The Boolean operator (OR) was used between the search keywords within each type of terms, while the Boolean operator (AND) was used between different types of terms.

Study Selection

Based on predetermined inclusion criteria, appropriate research articles were chosen. The inclusion criteria include 1) research articles issued in English in peer-reviewed journals, 2) The target population was children aged 18 years or younger, of both genders, 3) the children should be diagnosed with one of IDD, including ASD, DS, ADHD, and CP, 4) the study objectives include assessing nutritional status or dietary behaviors of children with IDD, and 5) the study should be conducted in Saudi Arabia. Assessing nutritional status could be seen as an anthropometric assessment, such as measuring height, weight, circumferences, or body mass index, laboratory assessment, such as measuring serum proteins, metabolites, electrolytes or vitamins, or dietary assessment, such as evaluating macronutrients and micronutrients intake. Assessing dietary behaviors could be seen as evaluating behaviors related to food such as daily meals and snacks frequency, mealtime behaviors, and feeding difficulties. The selection of appropriate studies was done in two stages. First, two separate authors evaluated the titles and abstracts of the gathered papers to determine their relevance based on the inclusion criteria. Second, the same two authors gathered and reviewed the complete texts of selected articles in the first stage to confirm their relevance for this systematic review. A third author compared the data gathered by each author after each phase, discussing and fine-tuning any discrepancies. The final list of appropriate studies was established.

Data Collection

The relevant data were gathered from the chosen research articles. The collected data include general characteristics of selected studies such as type of recruited cases, sample sizes, study design, objectives, and location. Then, the outcomes of interest, including anthropometric data, laboratory data, dietary intake data, or dietary behaviors data, were collected. Data collected from the included studies were organized in relevant tables.

Quality Assessment

The methodological quality and bias risk were evaluated by two authors. When there were discrepancies, a third author was consulted to settle any disputes. The Quality Criteria Checklist of the Academy of Nutrition and Dietetics was employed.²¹ The reviewers evaluated each study based on ten criteria, which included research question, selection, study groups comparable, withdrawals, blinding, intervention, outcomes, statistical analysis, conclusions supported by results, and funding or sponsorship.²¹ Following a review of the Methods section of each study, an overall rating was assigned using the Quality Criteria Checklist. If five or more items—including items 2, 3, 6, and 7—are answered “Yes”, the study is rated positively, and there is less chance of bias. A neutral rating is given if five or more items are marked as “Yes”, but the responses to questions 2, 3, 6, or 7 fail to indicate that the study is particularly strong. If the response to six or more items is “No”, the rating is considered negative.²¹

Results

Study Description

Out of 286 screened articles, 31 papers were selected (see Figure 1). The characteristics of selected articles are presented in Table 1. All articles were issued between 2003 and 2023. Most of them were targeted subjects diagnosed with ASD (n = 18), followed by DS (n = 7), CP (n = 3), and ADHD (n = 1), and two studies included subjects diagnosed with ASD, DS, and CP. The majority of the studies had observational study designs, either cross-sectional (n = 12) or case–control (n = 8). However, the study design for nine studies was not reported, although it can be implied that these studies were observational. One study was with a prospective design, while another study was with a retrospective design. Most studies were conducted in the city of Riyadh (n = 18), followed by Taif (n = 3), Madinah (n = 2), Makkah (n = 1), and Hail (n = 1), and two studies were recruited subjects from two different cities for each study. However, the study locations for four studies were not reported. Twenty-two out of 31 included studies recruited typically developing children as a control for comparison, in addition to recruitment of children with IDD (cases). The sample size varies considerably among different included articles. There was a range of 11 to 785 participants in the case group and 16 to 989 participants in the control group.

Figure 1 Flowchart illustrating the selection process for studies included in the systematic review.

Table 1 Characteristics of Selected Studies Included in the Systematic Review (n = 31)

Risk of Bias Assessment

Out of 31 papers, 15 articles had a positive rating, indicating a high-quality study and a lower risk of bias (Table 2). Furthermore, 16 studies had a neutral rating, demonstrating a study of moderate quality and risk of bias. Interestingly, no studies had been given a negative rating. Clear research questions were observed in all studies. Most studies were found to be free from selection bias (n = 25), and bias due to the study’s funding or sponsorship (n = 19), and had comparable study groups (n = 22), description of intervention/exposure in detail (n = 29), clear outcomes, valid and reliable measurements (n = 30), appropriate statistical analysis (n = 30), and conclusions that supported by Results (n = 21). However, a few studies were included a clear description of study withdrawal handling (n = 9), and only one study included blinding that was used to prevent the introduction of bias as most included selected studies had observational designs.

Table 2 Risk of Assessment Bias for Selected Studies Included in the Systematic Review (n = 31)

Systematic Review Findings

Anthropometric Data

Anthropometric data are shown in Table 3. Out of 31 selected articles, 15 studies involved anthropometric data. Collected anthropometric data includes height, weight, BMI, BMI categories, and others. Seven different studies reported data on each of the following measurements: height, weight, and BMI. In an attempt to develop growth charts for children with DS aged one month to five years, height, weight and BMI were reported based on gender for six age intervals.^22,23 For boys with DS, the BMI means were significantly lower than the control for age intervals 0–0.5 years, and 0.5–1 years, and significantly higher than the control for age intervals 3–4 years, and 4–5 years. For girls with DS, the BMI means were significantly lower than the control for age intervals 0–0.5 years, 0.5–1 years, and 1–2 years, and significantly higher than the control for age intervals 3–4 years, and 4–5 years.^22,23 Differences in height and weight were statistically not significant (P = 0.812) between autistic children and control.²⁴ Although children with DS were found to be significantly shorter than the control (P = 0.003), no significant differences in weight, or BMI between cases and control were observed.^25,26 A similar result was observed among children with DS stratified based on gender compared with control regarding height and weight.²⁷ However, boys and girls with DS significantly had greater BMI than control.²⁷ Although adolescents with DS were significantly shorter (P = 0.009) and had greater BMI (P = 0.029) than control, no significant difference in height, weight, or BMI between children with DS and control was reported.²⁸ Finally, the mean BMI for DS children was significantly higher than control.²⁹

The rates of overweight and obesity were included in nine studies. Two studies reported a greater prevalence of overweight and obesity in DS children compared with control.^25,29 Another study observed that the rate of obesity was greater in children and adolescents with DS compared with control.²⁸ The rate of obesity was found to be greater in autistic children compared with control in two reports.^30,31 Finally, four articles reported overweight and obesity rates in children with ASD, DS, and/or CP without comparing results with control.^32–35 Other reported anthropometric indicators include triceps skinfold thickness,²⁹ body fatness,^28,29 head circumference,^22,23 and z-scores for weight-for-height and weight-, height-, and BMI-for-age.³⁶

Table 3 Anthropometric Assessment Reported in Selected Studies Included in the Systematic Review (n = 15)

Laboratory Data

Laboratory data are presented in Table 4. Out of 31 selected studies, 12 studies involved laboratory data. Collected laboratory data include serum levels of selected vitamins, minerals, and fatty acids, and specific hematological indices. Five studies reported data on serum concentrations of vitamins D, C, and E. In comparison with control, one study found that serum level of vitamin D was significantly lower among ADHD children,³⁷ while another two studies found that serum level of vitamin D was significantly lower among autistic children.^38,39 In another study, the serum level of vitamin E, but not vitamin C, was significantly lower in autistic children than in the control.⁴⁰ Furthermore, two studies reported the rate of vitamin D deficiency.^41,42

Three studies reported data on serum levels of selected minerals among autistic children. These studies observed that autistic children had significantly lower serum concentrations of calcium and selenium, significantly higher serum concentrations of potassium, lead, and mercury than control, and/or no significant differences in serum concentrations of magnesium.^43–45

Table 4 Laboratory Results Reported in the Selected Studies That Included in the Systematic Review (n = 12)

Two studies reported data on serum levels of selected fatty acids among autistic children,^42,46 while serum fatty acid ratios were included in two studies.^46,47 One study observed that ASD children had significantly lower serum concentrations of several fatty acids such as a-linolenic, docosahexaenoic, and linoleic acids, significantly higher serum concentrations of certain fatty acids such as hexanoic, and stearidonic acids than control, and/or no significant differences in serum level of eicosapentaenoic acid.⁴² Finally, hematological indices were reported in one study as the percentage of abnormal values of hemoglobin, hematocrit, and RBC counts.³⁶

Dietary Intake Data

Results on dietary intake are presented in Table 5. Out of 31 selected studies, only four studies involved dietary intake data. One of these studies recruited only autistic children with no typically developing children as a control for comparison.³⁴ Collected dietary intake data include daily intake of energy, macronutrients, and micronutrients. Three studies reported data on energy intake. Even though differences were not significant, two studies found that energy intake was lower among children with DS and ASD, respectively, compared with control.^29,31 Contrarily, the third article observed that energy intake was significantly greater in autistic children than that reported for control.³⁰

Table 5 Dietary Intake Results Reported in the Selected Studies Included in the Systematic Review (n = 4)

One study reported a significantly lower intake of protein, fat, vitamin A, riboflavin, sodium, potassium, and calcium among children with DS than that reported for control, and no significant difference in dietary intake of carbohydrates, fiber, carotene, vitamin C, thiamin, phosphorus, and iron.²⁹ Another study reported a significantly greater intake of vitamin C, and potassium, and a significantly lower intake of folic acid, vitamin B12, sodium, calcium, iron, magnesium, and selenium in autistic children compared with control, and no significant difference in dietary intake of vitamin A, thiamin, riboflavin, vitamin B6, phosphorus, and zinc.³⁰ A third study observed a significantly lower intake of omega-3 fatty acids and iron among autistic children compared to the control, and no significant differences in dietary intake of carbohydrates, protein, fat, vitamin D, folic acid, vitamin B12, and calcium.³¹

Dietary Behaviors Data

Dietary behaviors data are presented in Table 6. Out of 31 selected studies, ten studies involved dietary behaviors data.^{27,28,31,34,36,48–52} Collected dietary behaviors data include daily rates of meal intake, healthy food intake, unhealthy food intake, mealtime behavior, and feeding difficulties. Five studies reported data on meal intake, including the frequency of daily consumption of regular meals, main meals including breakfast, lunch and dinner, and snacks. Six studies reported data on healthy food intake, including the frequency of daily consumption of dairy products milk, cheese, red meat, chicken, seafood, fish, tuna, liver, eggs, vegetables, fruits, fresh fruit juices, legumes, pasta, cereal, bread, rice, macaroni, butter, olive oil, water, and beverages. Similarly, six studies reported data on unhealthy food intake, including the frequency of daily consumption of fast food, junk foods, desserts, sweets, soft drinks, sweetened juice, and processed meat. Finally, only three studies reported data about mealtime behavior such as crying or screaming at mealtime, preferring sweet food, and eating meals with the family, while only two studies reported data about feeding difficulties like vomiting after meals, ability to chew and swallow food and appetite of the child. Generally, data exhibit that children with IDD are anticipated to have unhealthy dietary behavior compared with control.

Table 6 Types of Collected Data Related to Dietary Behavior Included in the Systematic Review (n = 10)

Discussion

This review is the first one to target the nutritional status and dietary behaviors of children with IDD in Saudi Arabia. Data on the nutritional status and dietary behaviors of children with IDD from this country are still limited and inconsistent, despite the observed rise in the rates of IDD in children in Saudi Arabia and the crucial role of nutritional status in the management of these types of disability. The results of this review showed that the quantity of the selected articles is generally low. Additionally, there was an extensive amount of disparity between the objectives and findings of different studies, which made it difficult to draw comprehensive conclusions. This could be explained by the impact of using various indicators to assess the nutritional status and dietary behaviors outcomes of children with IDD in these studies.

The results of anthropometric measurements show that the rates of overweight and obesity were significantly greater among children with IDD compared to control, despite that inconsistent results were shown in weight and BMI means of children with IDD compared to control. Although different studies used different cut-off points to determine obesity rates based on the BMI-for-age growth charts at the 95th or 97th percentile, many studies revealed that children with IDD were less expected to maintain normal body weight and were at higher risk of either gaining weight and developing obesity or losing weight and becoming underweight.⁵³ Consequences of neurodevelopmental disorders such as greater levels of growth hormone may contribute to the greater prevalence of obesity seen in children with IDD compared to control.⁵⁴ However, environmental factors such as unhealthy eating patterns and physical inactivity are still significant players in the development of obesity among these children.⁵⁵

The laboratory data revealed that children with IDD were more likely to have nutritional deficiencies compared with control. This could be related to restrictive diets and meal skipping usually observed among children with IDD.⁵⁶ Despite the limited number of studies, results confirm significantly lower levels of serum vitamin D among children with IDD. Vitamin D deficiency in these children could be related to inadequate sun exposure and limited outdoor daytime activities.⁵⁷ Furthermore, there is a high correlation between vitamin D deficiency and the severity of disability, indicating the importance of continuous monitoring of this nutrient among children with IDD.^58,59 Interestingly, variations in serum profile of fatty acids were reported among autistic children compared with control. These findings could be referred to variations in types of consumed dietary fats including saturated fats and omega-3 fats intake.^60,61

The results of a few studies that reported dietary intake data provide inconsistent results about intake of energy, macronutrients, and micronutrients in children with IDD compared with control. However, low intake of energy, protein, and several micronutrients is frequently reported among children with IDD.^62,63 This could be related to restrictive and selective diets usually observed among those children.^56,64 The identified variations in mealtime practices and food choices can potentially have an impact on nutritional status. Food intake might be restricted as a result of selective eating and food rejection, which might compromise the diet’s sufficiency in vital vitamins, minerals, and essential fatty acids.⁶⁵

Although there is a growing interest in scientific research regarding the prevalence of the nutritional status and dietary behaviors of children with IDD, the current evidence is still limited and modest.^55,66–70 A scoping review was conducted to identify evidence on the prevalence of nutritional status in children with DS, CP, and ASD.⁶⁶ Their results revealed that children with CP were at risk of being underweight, while children with DS and ASD were at risk of being overweight or obese.⁶⁶ The rate of overweight and obesity in children with DS ranged from 33.5% to 43.5%. The rate of underweight in children with CP ranged from 22.2% to 78.2%.⁶⁶ A systematic review that investigated the nutritional status and feeding behavior of autistic children in the Middle East North Africa found that both overweight and underweight, feeding behavior problems, and nutritional deficiencies such as iron, calcium, vitamin B12, folate, and vitamin D were common.⁵⁵ Contrarily, another systematic review investigated the anthropometric measurements and nutritional assessment in individuals with autism and reported inconsistent results.⁶⁷ While some reports have found that autistic children are at risk of being overweight or obese, other studies have suggested that autistic children are at risk of having lower BMI.⁶⁷ Moreover, they reported contradictory results regarding the adequacy of dietary intake of autistic children.⁶⁷ A recent systematic review that was carried out to assess the rate of malnutrition among children with CP found that the prevalence of malnutrition was 40% and certain nutritional deficiencies such as hypocalcemia and reduced serum concentrations of zinc, copper, and vitamin D were commonly reported.⁶⁸ Another systematic review was conducted to evaluate the nutritional interventions in children and adolescents with CP and reported that children and adolescents with CP have worse nutritional status than control.⁶⁹ Finally, a recent systematic review studied the clinical implications of adequate nutrition in children and adolescents with ADHD. They reported that the daily intake of calories and nutrients in those treated with methylphenidate is commonly lower than control.⁷⁰

This review had a few limitations. The search strategy was narrowed to research papers that were written in English in reliable databases to ensure including good-quality reports. Unfortunately, most of the relevant research articles that were published in Arabic languages were of low quality. The language restrictions we did would strengthen the credibility of this review, even if it would impact the availability of relevant studies. The second limitation was the scarcity of available research studies that assess the nutritional status and dietary behaviors of children with IDD in Saudi Arabia. The potential impact of nutritional status on the health outcomes of children with IDD is an emerging field of research in Saudi Arabia.¹⁷ This review could invite researchers and academicians in Saudi Arabia to put more effort into this important research area. Furthermore, a high disparity in measured outcomes in the included studies was noted. However, the present systematic review is the first one that was conducted to examine the obtainable data from research articles carried out to evaluate the nutritional status and dietary behaviors of children with IDD in Saudi Arabia. The analysis of the quality of included studies in this review showed that the quality of the selected articles is generally moderate (neutral rating) to high (positive rating). Interestingly, no studies had been given a negative rating which indicates a low-quality research article. This could support the credibility and the overall conclusions of this review. The results of this study will advance our understanding of the nutritional status and dietary behaviors of children with IDD in Saudi Arabia.

Research evidence provided in this review indicates that children with IDD are highly susceptible to malnutrition, which could impact their health and development. Further research is required to determine the types of intervention measures that can be taken to reduce the detrimental effect of malnutrition on the health and development of children with IDD. Adopting a healthy diet and minimizing unhealthy dietary behaviors are currently important approaches used to lower the risk of malnutrition among children with IDD. More studies are needed to determine the impact of various dietary behaviors on the health quality and nutritional status of these children. Furthermore, the mechanisms by which specific micronutrients impact the nutritional status of children with IDD are poorly understood. Further research is required to determine the effect of different micronutrients on the nutritional status of children with IDD using longitudinal designs or controlled interventions.

Conclusion

Results of the current study indicate that children with IDD are considered at higher risk for malnutrition. Therefore, healthy and balanced nutrition that considers dietary requirements and food preferences is critical to maintain optimal development of these children. Continuous monitoring of the nutritional status of children with IDD is recommended and helpful in planning timely and appropriate nutritional intervention when necessary. Moreover, improving family diets is a key factor in reducing the number of disabled children in the future. Converting to a healthy diet and reducing the consumption of ultra-processed foods is a crucial approach used to decrease serum heavy metals and enhance behaviors and learning among children with IDD. With IDD prevalence rising at worrying rates at the population level, it is evident that more work needs to be done at the health policy level to enhance the health quality and nutritional status of children with IDD. Prominently, advancements should be made in the health care system by establishing health and nutrition screening and education programs oriented toward this in-need group of the community and their families. The introduction of policies that aid in monitoring the nutritional status and dietary behaviors of children with IDD will help to improve their health and development. Future studies with robust and appropriate methods are needed to assess various aspects of the nutritional status and dietary behaviors of children with IDD in Saudi Arabia.