While past interventions have effectively managed gestational weight gain (GWG) in normal weight women, most have been unsuccessful with regulating GWG in pregnant women with overweight/obesity (PW-OW/OB). To address this, we developed an individually-tailored, adaptive intervention, Healthy Mom Zone, based on a dynamical model of energy balance to manage energy intake (EI) and promote energy expenditure (EE) in an effort to effectively regulate GWG in PW-OW/OB. We previously reported the increase in GWG from pre-to-post intervention was less for the intervention group (INT; M=15 pounds) than controls (CON; M=19 pounds). The purpose of this analysis was to examine change in EI and EE by study group.


PW-OW/OB (N=31; 52% OB) were randomized to INT (n=15) or CON (n=16) from ~9-36 weeks gestation and completed daily measures of EE (activity kcal; Jawbone activity monitor). We used a back-calculation method to estimate EI kcal given high rates of under-reporting bias. General linear models with correlated errors were fit and contrasts constructed to compare change (post-pre) within and between groups for EI/EE.


As expected with pregnancy, back-calculated EI kcal increased from pre-to-post for INT (pre: 2777, post: 3188) and CON (pre: 2377, post: 3512); however, the increase in kcal was significantly less for INT (M=410) than CON (M=1135), p=.02. There was no significant change in EE for either INT or CON (p>.05). However, exploratory analyses by weight groups showed EE kcal in women with obesity significantly increased from pre-to-post for INT (M=447) while decreased for CON (M=-144); p=.02; there was no significant change in EE kcal in women with overweight, although examination of means showed an increase for INT (M=70) and decrease for CON (M=-23).


These findings suggest an individually-tailored, adaptive GWG intervention shows initial promise for helping PW-OW/OB regulate their EI, and specifically for women with obesity,moderate a decline in EE over pregnancy.