Plain language summary
Bulimia nervosa (BN) is characterised by episodes of compulsive binge eating and compensatory behaviours such as restriction/fasting, over exercising or self-induced purging. Research suggests that sufferers may have alterations in their food evaluations and the cephalic phase of eating. This study explores whether the oral sensory responses from high fat liquids compared to non-fat liquids were different in BN subjects compared to healthy controls. The hormonal responses to each liquid were qualified by measuring glucose, insulin, ghrelin and pancreatic polypeptides (which have been found to be associated with cephalic phase of eating solid foods). Subjective hunger levels were also measured. Participants were 10 women aged between 18 and 42 years, and the control group consisted of 11 women without an eating disorder. The study found not significant differences between the fat and non-fat liquids in terms of hunger levels or hormonal responses. However, there were differences between the BN group and the control. BN compared to controls had higher levels of hunger at baseline. BN's also rated the liquids 'fattier' tasting regardless of the fat content of the liquids and also reported a 'fear of swallowing' more than the control group. There were also differences between the BN and control group in baseline hormonal levels - BN's had significantly elevated ghrelin and pancreatic polypeptide levels. BN's also had elevated ghrelin levels throughout. The authors concluded that BN women have different orosensory responses that are not influenced by opioid receptor antagonism, evident in hormonal responses, or dependent on the fat content of a similarly textured liquid.
Abstract
Sensory evaluation of food involves endogenous opioid mechanisms. Bulimics typically limit their food choices to low-fat "safe foods" and intermittently lose control and binge on high-fat "risk foods". The aim of this study was to determine whether the oral sensory effects of a fat versus a non-fat milk product (i.e., traditional versus non-fat half-and-half) resulted in different subjective and hormonal responses in bulimic women (n=10) compared with healthy women (n=11). Naltrexone (50mg PO) or placebo was administered 1h before, and blood sampling began 30 min prior to and 29 min after, a 3 min portion controlled modified sham-feeding trial. Following an overnight fast, three morning trials (fat, naltrexone; fat, placebo; and non-fat, placebo) were administered in a random double-blind fashion separated by at least 3 days. Overall, there were no differences between Fat and Non-Fat trials. Hunger ratings (p<0.001) and pancreatic polypeptide levels (p<0.05) were higher for bulimics at baseline. Bulimics also had overall higher ratings for nausea (p<0.05), fatty taste (p<0.01), and fear of swallowing (p<0.005). Bulimics had approximately 40% higher total ghrelin levels at all time points (p<0.001). Hormones and glucose levels were not altered by the modified sham-feeding paradigm. Naltrexone, however, resulted in an overall increase in blood glucose and decrease in ghrelin levels in both groups (p<0.05, for both). These data suggest that bulimic women have different orosensory responses that are not influenced by opioid receptor antagonism, evident in hormonal responses, or dependent on the fat content of a similarly textured liquid.
Methodological quality
Allocation concealment
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Yes
