The effects of vigour on measures of obesity across time.
OBJECTIVE
Past studies expected measures of obesity to be positively associated with positive affects. However, this hypothesis was not tested in reference to a specific positive affect. We tested the hypothesized unidirectional effects of measures of obesity on vigour, representing a positive affect, and of vigour on measures of obesity.


METHODS
We used a longitudinal design, separately for men and women. Participants were 1,876 and 931 healthy men and women, respectively, examined at Time 1 (T1) and Time 2 (T2), about 2 years apart.


METHODS
Measures of obesity included body mass index, waist circumference, and waist-to-hip ratio. Vigour was assessed by the Shirom-Melamed Vigour Measure. We used structural equation modelling to test our hypotheses.


RESULTS
We found that for both genders, T1 measures of obesity did not predict either T1 or T2 vigour. Among both genders, we found support for the effects of T1 vigour on T1 but not on T2 measures of obesity.


CONCLUSIONS
To the extent that the 'Jolly fat hypothesis' refers to the effects of measures of obesity on positive affects, we failed to support it for vigour as a positive affect. Vigour has contemporaneous but not longitudinal effects on body weight.
Tel Aviv University, Israel Academic College of Tel Aviv-Yaffo, Tel Aviv, Israel. ashirom@post.tau.ac.il
Arie
A
Shirom
Samuel
S
Melamed
Shlomo
S
Berliner
Itzhak
I
Shapira
D000328:Adult; D000339:Affect; D015992:Body Mass Index; D004651:Employment / Q000523:psychology*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D007557:Israel; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000523:psychology*