Calories

What are Calories?

  • Calories provide energy for the body. Our bodies take calories from all foods in order to function properly and are required. 

  • Children with ASD have been shown to either consume too many or too few calories/nutrients and therefore have been shown to be at an increased risk of becoming overweight/obese or malnourished.

  • The calorie you see on food packages is actually a kilocalories (abbreviated kcal), or 1000 calories. 

  • Calories are a unit of measurement that describes how much energy it would take to raise 1 kg of water 1 degree celsius.

  • Our bodies use calories from food in 3 ways: 

    • ~10% of calories are utilized for digestion 

    • ~20% for physical activity 

    • ~70% for basic metabolic function 

Sources of Calories

  • Not all calories function the same. Carbohydrates high in fiber resist both digestion and absorption so they contribute less energy. [13]

    • For example: 100 calories of spinach contributes less energy in the body than 100 calories of potato chips consumed  

  • Though fat has the most calories per gram, it is an important macronutrient that can aid in brain development and function. 

  • Therefore, there is more to following a healthy diet than counting calories. Choosing nutrient-rich foods plays an important part too.

Recommended Intake

These recommendations are based on the Recommended Dietary Allowance (RDA), which is the average daily level of intake sufficient to meet the nutrient recommendations of nearly all (97-98%) of healthy individuals [2].

Note: Calorie is abbreviated kcal (short for kilocalorie). Kilogram is abbreviated kg. A kilogram is 2.2 pounds. To calculate your child’s calorie needs, divide their weight in pounds by 2.2, and then multiply it by the calorie amount specified below for their age.

Infants/Children 

  • o-6 months: 85-100 kcal/kg 

  • 7-12 months: 80-82 kcal/kg 

  • 1-3 years: 80-85 kcal/kg 

  • 4-8 years: 60-70 kcal/kg  

Males  

  • 9-13 years: 45-50 kcal/kg

  • 14-18 years: 35-40 kcal/kg 

Females

  • 9-13 years: 40-45 kcal/kg 

  • 14-18 years: 30-35 kcal/kg  


This list is a recommendation but every person is unique in determining the exact amount of calories he or she needs.  Physical activity level, age, body size, gut bacteria health, and enzyme levels are just a few of the factors that determine the number of calories an individual needs.  

Under-Consumption of Calories

  • Malnutrition occurs when there is underconsumption of nutrients and/or energy. 

  • Consuming too few calories can lead to low energy, fatigue, and body dysfunction 

  • Lack of a diverse diet can cause energy and nutrient deficiency  

    • Children with ASD ages 4-11 were shown to consume significantly less energy, vitamin A, vitamin C, and zinc[ 3]. Likely related to the prevalence of abnormal/selective eating behaviors in children with ASD.  

    • Individuals with ASD are 70% more likely to demonstrate gastrointestinal issues such as diarrhea, constipation, food sensitivities, allergies, and intolerances (see: Food Reactions) [6].  Gastrointestinal issues can all contribute to lower consumption of calories due to discomfort and malaise [12].  

  • Signs of malnutrition include fatigue, dizziness, and weight loss. 

  • Risk factors for malnutrition  

    • Individuals with selective eating or atypical eating behaviors. This is also known as being a “picky eater”. This can be a common occurrence in children with ASD. One study showed that 70-90% of parents with a child diagnosed with ASD reported their child to be a selective or picky eater [7]. To read more about picky eating, click here

    • Lack of a diverse diet can cause nutrient deficiency. One study showed that selective eaters were significantly more likely to be deficient in one or more nutrients [8]. 

    • Individuals on antipsychotic medications commonly used to treat anxiety disorders. These include a class of drugs called serotonin reuptake inhibitors (SRIs) which have shown to cause a lack of appetite [1].  

Over-Consumption of Calories

  • Over-consumption of energy, or a lack of physical activity, or a combination of both can cause an accumulation of excess body fat or adipose tissue.   

    • Obesity in children is classified as a BMI-for-age at or above the 95th percentile and overweight is classified as a BMI-for-age at or about the 85th percentile [4].

  • Those classified as overweight/obese are at an increased risk for insulin disfunction, diabetes, cardiovascular disease, some cancers, and other chronic diseases [5].

  • Individuals at increased risk of over-consumption of calories include those who report: 

Supplements

If your child is underweight and you are looking to increase calorie consumption, consider nutrient-dense foods such as fats and oils (these contain 9 calories/gram vs 4 calories/gram in protein and carbohydrates). Examples include avocados, nuts, and healthy oils. See the fat note for more examples. MCT Oil is a supplement that can be used to boost calories in the diet.

You may also consider adding Protein Supplements to increase calorie intake. It can be easier for some children to drink calories rather than eating them.

If your child is overweight or obese, remember that not all calories act the same on the body. Foods high in fiber can increase satiety, or the feeling of fullness, compared to lower fiber foods with equal calories. Adding more high fiber foods or supplements can regulate blood sugar, reduce the risk of chronic disease, and promote a healthy weight. Read more about fiber supplementation here and see more high-fiber foods here.

DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.

Calories & Autism in the Research

There are no current studies on autism and calories, though there are various studies measuring underweight and overweight in children with autism.

Obesity and Autism  

  • One study found that children ages 2-5 with ASD were more likely to be classified as overweight or obese [3].   

  • Multiple studies have shown the prevalence of obesity in children with ASD and significant consequences this can have on health, including the prevalence of cardiovascular disease and diabetes [9] [10] [11]. 


Malnourishment and Autism 

  • One study showed that children between the ages of 6-11 were more likely to be classified as underweight [3].   

Food Quality and Autism  

  • Children with ASD were more likely to be classified as a selective or picky eater than their typically developing peers. Multiple studies show that though caloric intake is roughly the same as typically developing individuals, individuals with ASD were shown to choose less nutrient dense foods which can lead to deficiency [7] [8].  

  • One study found that on average, children with ASD were shown to consume ~20% protein in their diet [8]. 


  • [1] Curtin C, Jojic M, Bandini LG. Obesity in children with autism spectrum disorder. Harv Rev Psychiatry. 2014;22(2):93-103. doi:10.1097/HRP.0000000000000031

    [2] Dietary Reference Intakes for Energy, Carbohydrate. Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2002/2005). This report may be accessed via www.nap.edu.

    [3] Hyman SL, Stewart PA, Schmidt B, Cain U, Lemcke N, Foley JT, Peck R, Clemons T, Reynolds A, Johnson C, Handen B, James SJ, Courtney PM, Molloy C, Ng PK. Nutrient intake from food in children with autism. Pediatrics. 2012 Nov;130 Suppl 2(Suppl 2):S145-53. doi: 10.1542/peds.2012-0900L. PMID: 23118245; PMCID: PMC4536585.  

    [4] Krebs NF, Himes JH, Jacobson D, Nicklas TA, Guilday P, Styne D. Assessment of child and adolescent overweight and obesity. Pediatrics. 2007;120(Suppl):S193–228. doi: 10.1542/peds.2007-2329D. 

    [5]  Must A, Strauss RS. Risks and consequences of childhood and adolescent obesity. [Accessed March 3, 2013];International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity. 1999 23(Suppl 2):S2–11 

    [6]  Buie E , Campbell DB, Fuchs GJIII, et al. . Evaluation, diagnosis, and treatment of gastrointestinal disorders in individuals with ASDs: a consensus report. Pediatrics. 2010;125:1–18. 

    [7] Ristori MV, Quagliariello A, Reddel S, et al. Autism, Gastrointestinal Symptoms and Modulation of Gut Microbiota by Nutritional Interventions. Nutrients. 2019;11(11):2812. Published 2019 Nov 18. doi:10.3390/nu11112812 

    [8] Zimmer, M.H., et al., Food variety as a predictor of nutritional status among children with autism. Journal of Autism & Developmental Disorders, 2012. 42(4): p. 549-56 

    [9] Tyler CV , Schramm SC, Karafa M, et al. . Chronic disease risks in young adults with autism spectrum disorder: forewarned is forearmed. Am J Intellect Dev Disabil. 2011;116:371–380. 

    [10] Curtin C , Anderson SE, Must A, Bandini L. The prevalence of obesity in children with autism: a secondary data analysis using nationally representative data from the National Survey of Children's Health. BMC Pediatr. 2010;10:11. 

    [11] Sudha M. Srinivasan, Linda S. Pescatello, Anjana N. Bhat, Current Perspectives on Physical Activity and Exercise Recommendations for Children and Adolescents With Autism Spectrum Disorders, Physical Therapy, Volume 94, Issue 6, 1 June 2014, Pages 875–889, https://doi-org.webproxy2.ouhsc.edu/10.2522/ptj.20130157 

    [12] Reference: Ristori MV, Quagliariello A, Reddel S, et al. Autism, Gastrointestinal Symptoms and Modulation of Gut Microbiota by Nutritional Interventions. Nutrients. 2019;11(11):2812. Published 2019 Nov 18. doi:10.3390/nu11112812 

    [13] Hervik AK, Svihus B. The Role of Fiber in Energy Balance. J Nutr Metab. 2019;2019:4983657. Published 2019 Jan 21. doi:10.1155/2019/4983657

Authors

Contributed by Brittyn Coleman, MS, RDN/LD, CLT

Suzy Morris, Dietetic Intern

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