Background

Scant data exist on weight loss interventions for youth with intellectual disabilities (ID).

Objective

To compare weight loss among youth with ID randomized to a 6-month, family-based behavioural intervention (FBBI) or a waitlist and to compare weight loss among youth who completed a 6-month maintenance (FBBI-M) intervention to a control group (FBBI-C).

Methods

Youth with ID and overweight/obesity, aged 14-22 years, were randomized to the FBBI or to a waitlist and subsequently randomized to a maintenance intervention or a control group. Sessions were held weekly during the FBBI and biweekly during the FBBI-M. Using an intention-to-treat approach, we used linear mixed models to test differences in the change in weight and in BMI from the start of FBBI.

Results

The 24 participants who received the FBBI lost, on average (SE), 5.1 (1.1) kg (P < .001) over 6 months. The 13 participants who were waitlisted gained, on average (SE), 1.2 (1.6) kg over the 6-month waiting period. At 12 months, those who received FBBI-M lost, on average (SE), 4.4 (1.7) kg more than those who received FBBI-C (-7.6 vs -3.2 kg, P-value = .008).

Conclusion

Participation in an intensive FBBI for weight loss with ID was efficacious, and continued participation in a maintenance intervention yielded additional weight loss.

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decreasing GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages.