Disentangling consequences of self-perceived weight from excess adiposity in metabolically healthy overweight/obesity.

backgroundGreater self-perceived weight is detrimental to cardiometabolic health among people with overweight/obesity. However, it is impractical to test and unknown whether weight-related psychosocial factors, like self-perceived weight, independently affect cardiometabolic health apart from physiological dysregulation produced by excess adiposity among people with overweight/obesity. Metabolically healthy overweight/obesity (MHOv/Ob) involves overweight/obesity, but with the absence of metabolic dysfunction. The MHOv/Ob phenotype may be a promising model to examine unique contributions of self-perceived weight to long-term changes in metabolic health. We tested whether self-perceived weight independently contributes to declining metabolic health by comparing people with MHOv/Ob and metabolically healthy normal weight (MHNW). We hypothesized that: (1) those with MHOv/Ob are more likely to become metabolically unhealthy and gain BMI at follow-up (7-11 years later) compared to MHNW, and (2) these transitions in metabolic health and BMI among those with MHOv/Ob will be mediated by higher self-perceived weight.

methodsUsing data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), we classified metabolically healthy participants by weight status (normal weight, overweight, obesity) at Wave IV (ages 25-33). We tested whether longitudinal transitions from a metabolically healthy to unhealthy state (n = 788) and changes in BMI (n = 901) among MHOv/Ob (vs. MHNW) participants were mediated by higher self-perceived weight at Wave V (ages 33-43).

resultsThe MHOv/Ob (vs. MHNW) groups had greater odds of becoming metabolically unhealthy at Wave V (overweight odds ratio [OR]: 3.85 [1.87, 7.94], obesity OR: 9.12 [5.01, 16.61]). However, those with metabolically healthy obesity exhibited decreasing BMI (β: - 0.98 [- 1.75, - 020]). Although self-perceived weight was higher among the MHOv/Ob group, it did not mediate the relationship between Wave IV weight status and Wave V metabolic health (indirect effects-overweight risk difference (RD): 0.0046 [- 0.025, 0.033]; obesity RD: 0.0095 [- 0.050, 0.071]) or change in BMI (indirect effects-overweight β: - 0.30 [- 2.38, 1.75]; obesity β: - 0.51 [- 4.02, 2.84]).

conclusionsSelf-perceived weight alone may not contribute to long-term metabolic dysfunction over-and-above physiological strain of excess adiposity among those living with overweight/obesity. However, future research on determinants of MHOv/Ob phenotypes should examine the role of other weight-related psychosocial factors such as weight stigma.