Taste Acuity of the Morbidly Obese before and after Gastric Bypass Surgery

Abstract

Obese individuals have an increased preference for high caloric foods, such as sweets and fats. However, following gastric bypass (GBP) surgery, morbidly obese patients tend to avoid these foods. We hypothesize that this aversion may occur, in part, from permutations in taste acuity. To test this hypothesis, taste detection and recognition thresholds for the four basic tastes (salt, sweet, sour, and bitter) were assessed using a modification of the Henkin forced choice three stimulus technique. Taste acuity measurements were obtained at baseline and at 30, 60, and 90 days post-operative for six morbidly obese GBP women and ten non-surgical, lean female controls. We found nonsignificant differences in taste detection and recognition thresholds between morbidly obese and lean control study subjects at baseline, and no significant correlation between taste acuity and body size. Furthermore, in our study population of lean and obese women, ages 26 to 52, there were no significant interrelationships between baseline taste thresholds and known effectors of taste acuity, i.e., zinc levels, glycemic status, liver and kidney function, or age. Following GBP surgery, a significant up-regulation in taste acuity for bitter and sour was observed along with a trend toward a reduction in salt and sweet detection and recognition thresholds. These findings would suggest the following: (1) taste acuity does not influence taste preferences of the obese individual who has not had bariatric surgery; (2) taste effectors such as zinc, when within the range of normal values, do not alter thresholds of the 4 basic tastes; and (3) weight loss following gastric bypass surgery is associated with an up-regulation in taste acuity in the morbidly obese. Studies are currently under investigation at our center to identify the specific etiology of taste acuity upregulation in the morbidly obese following GBP surgery.

Zinc status and taste acuity in older Europeans: the ZENITH study

“…It is generally assumed that zinc status, when within the normal range, does not affect taste thresholds (Scruggs et al, 1994). On the contrary, these results imply that decline in salt and sour taste corresponds to zinc depletion in healthy ageing.…”

Changes in the salivary protein profile of morbidly obese women either previously subjected to bariatric surgery or not

“…Moreover, levels of salivary CA VI have been suggested as being positively associated with bitter taste perception [6], although there is some controversy regarding this issue [16,35]. There are conflicting results regarding the effect of bariatric surgery on bitter taste perception (some authors report changes [41], while others do not [5]). However, if it is assumed that the reports of studies relating PRPs, cystatin S, and CA VI abundance with bitter taste sensitivity are correct, this surgical procedure may be suggested as being related to a decrease in bitter taste sensitivity.…”

Metabolic surgery and cancer

“…31,57 The mechanisms for weight loss after metabolic surgery are muiltifactorial 11,12 and include the modulation of gut hormones that lead to alterations in appetite, hunger, dietary feeding behavior, and, more recently, taste modulation in addition to alterations in metabolic rate and resting energy expenditure. 11,58,59 Although, traditionally, surgery was considered to achieve weight loss through the malabsorption of food and restriction of stomach size, there is some discrepancy supporting the effects of stomach-pouch size or calorific malabsorption other than for a minority of procedures (such as the biliopancreatic diversion). 11,60 Surgery does, however, achieve a sustained decrease in caloric intake, 61,62 which has a long-standing association with decreased carcinogenesis in several experimental models that span over a century of research.…”