Bariatric surgery reduces body weight, but creates the need for surgical correction of the patient's body shape, especially of the abdomen. The abdominal skin of the ex-obese has a lower quantity of fibrous and non-fibrous components; however, its functional status has not yet been studied. This study quantified, at different depths, the neurological function of the abdominal skin of the obese and morbidly ex-obese. Semmes-Weinstein monofilaments were used to quantify sensory levels of abdominal skin at the supra-umbilical (SU), umbilical (U), and infra-umbilical (IU) levels in 25 currently morbidly obese, 56 post-bariatric patients (open Roux-en-Y gastric bypass), and 43 women with normal body weight and/or overweight without previous obesity (control). Only the control group showed a positive correlation between a worsening of sensory perception and age (p = 0.02). In the morbid obesity group, sensory threshold was higher at the IU level (9.60g/mm(2)) than at the U (5.86g/mm(2)) and SU (5.38g/mm(2)) levels (p < 0.05). The mean sensory threshold for morbid obesity subjects (6.95g/mm(2)) was higher than that of the post-bariatric patients (4.44g/mm(2)), which in turn was higher than that of the control group (3.47g/mm(2)), p < 0.01. Morbidly obese and post-bariatric patients have lost the normal positive correlation between age and skin sensitiveness. The IU region has sensitiveness compromised in morbid obesity. Sensory thresholds in post-bariatric patients showed improvement relative to morbidly obese, but remained worse than the control subjects.