The "jolly fat" for the middle-aged and older adults in China, was education level considered?

Background: Several studies have found a negative association between obesity and depression in Chinese middle-aged and elderly, suggesting the existence of "jolly fat". This study aims to investigate whether "jolly fat" is applicable among middle-aged and elderly with different education levels, and to provide a new perspective for depression screening and obesity interventions in middle-aged and older adults.

Methods: 10,018 individuals aged 45 years and over in China Family Panel Study (2018) were selected for analysis. A short version of Center for Epidemiological Research Depression Scale was used to assess depression. Body mass index was applied to define obesity status. Subgroup analysis of multiple logistic regression was performed to explore whether the relationship between obesity and depression was influenced by education levels.

Results: The prevalence of obesity and depression was 9.02 % and 22.96 % among participants. Obesity reduced the probability of depression in middle-aged and elderly with primary school education or below (OR = 0.71, 95 % CI = 0.56-0.91) while not affecting those with junior high school education or above (OR = 0.80, 95 % CI = 0.57-1.13).

Limitations: The results cannot be interpreted as causality due to the cross-sectional design. Besides, we cannot directly measure the body composition of the participants.

Conclusions: "Jolly fat" existed among middle-aged and elderly with low education, but not in those with junior high school education or above. Health care providers need to monitor the psychological status of low-educated middle-aged and older adults who are seen as needing to lose weight, while the underweight group should be the key target of depression screening.