Parent factors associated with BMI, diet, and physical activity of adolescents with intellectual and developmental disabilities.

Everything was measured at one point in time, so the paper can show only that these things travel together, not that one causes the other. The authors state this themselves. Only one parent per family answered the survey, nearly always the mother, so nothing is known about fathers or other caregivers. Almost the whole sample was white, so the researchers could not examine whether parent race or ethnicity matters. The sedentary-time result for parent education is reported twice in the same section with opposite conclusions: one sentence reports a difference of 515.2 versus 463.9 minutes a day, another says education had no influence on sedentary time. Valid accelerometer data existed for only 68 of the 95 adolescents (72%), so the activity findings rest on a smaller group that may not represent the whole sample. Diet quality and activity were poor across the entire group, and the authors suggest this may be why income made no difference to them. This is 95 families from a single trial of adolescents who were already overweight or obese, so the findings describe this group rather than adolescents with intellectual or developmental disability generally.

The text supplied contains no funding statement and no conflict-of-interest declaration. The article is indexed as receiving NIH extramural research support.

Do not read this as showing that a parent's weight, income or education causes a teenager's weight problem. These are single time-point measurements in 95 families, and the authors state the design cannot show cause and effect. Nor is there evidence here that changing any parent factor would change what an adolescent eats or how much they move, because parent BMI and income were not linked to any of those behaviours.