Marked differences in gustatory and gastrointestinal sensitivity to oleic acid between lean and obese men

Abstract

The ability to detect oleic acid both orally and within the gastrointestinal tract is compromised in obese men, and oral and gastrointestinal responses to oleic acid are related. This trial was registered at www.actr.org.au (Australian New Zealand Clinical Trials Registry) as 12609000557235.

Recent fat intake modulates fat taste sensitivity in lean and overweight subjects

“…24 Further to this, attenuated GI sensitivity has been reported among OB males, who consume excess dietary fat. 5 Based on fundamental similarities in receptor-mediated fatty acid detection within taste receptor cells and enteroendocrine cells of GI tract (CD36 Fat intake modulates fat taste sensitivity JE Stewart and RSJ Keast and G protein receptors 120, 40 and 43), 8,9 it is suspected that oral fatty acid detection and adaptations to fat exposure would mirror events that occur in the GI tract. Indeed modulation of fatty acid taste receptor expression has recently been reported in rodents exposed to a high-fat diet, 25 elucidating that physical changes in taste receptor expression can be induced by a high-fat diet.…”

“…[1][2][3] In obesity, both GI and taste detection of fatty acids is attenuated and this may predispose individuals to increased consumption of high-fat foods, or foods containing greater concentrations of fat. 4,5 For example, sensitivity to oleic acid (C18:1) in the oral cavity and GI tract is inversely associated with dietary fat intake, 4,5 and attenuated basal and phasic pyloric pressures, as well as accelerated gastric emptying have been reported following exposure to a high-fat diet. 6,7 These data suggest two possibilities: first, that consumption of a high-fat diet induces adaptive changes in GI fatty acid sensitivity, thus encouraging excess fat intake, and perhaps the development of obesity or, second, that genetic predisposition determines individual fatty acid sensitivity and/or insensitivity, of which the latter is a causal factor in development of obesity.…”

“…The environmental determinants of fatty acid taste remain undisclosed, however, prior studies that have reported attenuated fatty acid taste among obese (OB) persons, alongside an inverse association between fatty acid taste sensitivity and fat consumption, 4,5 suggest diet may have a significant role. Given that fatty acids are detected by homologous receptors within the oral epithelium and GI tract (CD36 and G protein receptors 120, 40 and 43), 8,9 it is suspected that oral fatty acid detection and adaptations to fat exposure, mirror events that occur in the GI tract, where both physiological and physical adaptations to high-fat exposure are well documented.…”

Gastric emptying, mouth-to-cecum transit, and glycemic, insulin, incretin, and energy intake responses to a mixed-nutrient liquid in lean, overweight, and obese males

“…Human obesity is associated with an increased preference for fatty foods, suggesting that fat intake is poorly regulated in this group (39). Postprandial plasma peptide YY, which is stimulated by dietary fat, has been reported to be reduced (23) or comparable (5) in obese vs. lean individuals, and there is evidence that obese individuals have a compromised ability to detect fatty acids both in the oral cavity and small intestinal lumen (39).…”

“…Postprandial plasma peptide YY, which is stimulated by dietary fat, has been reported to be reduced (23) or comparable (5) in obese vs. lean individuals, and there is evidence that obese individuals have a compromised ability to detect fatty acids both in the oral cavity and small intestinal lumen (39). Obesity is well recognized as a risk factor for a number of disorders, perhaps most importantly type 2 diabetes (33), and glycemic variability, which appears to be a determinant of macrovascular disease, may also be increased in the obese (25).…”