External-cue responsivity as a function of age at onset of obesity

Sixty subjects, averaging 26 per cent overweight, were classified according to age at onset in order to test the external-cue hypothesis of obesity and to investigate the possibility of different "types" of obesity. Subjects were presented with Hershey's kisses wrapped in either transparent (visible) or non-transparent (non-visible) wrappers while performing a sham test; the number of chocolates consumed was the dependent measure. Subjects were placed in four groups: Early onset-food visible (EV), early onset-food non-visible (ENV), late onset-food visible (LV), or late onset-food non-visible (LNV). The first two groups consumed about the same number of chocolates, but the early-onset subjects ate almost twice as many kisses as the late-onset participants. The evidence was inconclusive concerning the external-cue hypothesis, although there was some suggestion that there may be "types" of obesity. The findings are discussed in terms of the need to acknowledge factors other than weight alone in studying and treating obesity.