Neumeyer AM, et al. - Given the possible contribution of diet and exercise to lower bone mineral density (BMD) among boys with autism spectrum disorder (ASD) compared to typically developing controls, researchers herein assessed macro- and micronutrient intakes and self-reported physical activity in both of these groups and the association of these variables with BMD. Boys with ASD vs typically developing controls were found to have lower protein, calcium, and phosphorus intakes, activity levels, and BMD z scores at the lumbar spine, femoral neck, total hip, and whole body less head. Additionally, the positive association of protein, calcium, and phosphorus intakes with BMD was apparent.

• This cross-sectional study included a total of 49 adolescent boys (25 ASD, 24 typically developing controls), aged 8 to 17 years, recruited from a clinic population (ASD) or community advertisements (ASD and typically developing controls) matched for age.
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• All the study participants were assessed for 3-day food records and physical activity records, and BMD of the whole body less head, hip, and spine using dual-energy x-ray absorptiometry.
• Participants were also examined for fasting levels of 25(OH) vitamin D and calcium.

• Data showed that ASD participants were approximately 9 months younger than typically developing control participants on average.
• Researchers found that body mass index and serum vitamin D and calcium levels were similar.
• They also noted that compared with typically developing controls, boys with ASD consumed 16% fewer calories, with a larger percentage obtained from carbohydrates, and 37% less animal protein and 20% less fat.
• Additionally, a lower proportion of ASD participants were categorized as “very physically active” (27% vs 79%; P<0.001).
• Relative to typically developing controls, boys with ASD had 0.7 to 1.2 standard deviations lower BMD z scores at all locations.
• In boys with ASD, positive associations of higher animal protein, calcium, and phosphorus intakes with bone density measures were apparent.