RESUMEN
OBJECTIVE: To investigate the effect of nutrient stimulation of gut hormones by oligofructose supplementation on appetite, energy intake (EI), body weight (BW) and adiposity in overweight and obese volunteers. METHODS: In a parallel, single-blind and placebo-controlled study, 22 healthy overweight and obese volunteers were randomly allocated to receive 30 g day(-1) oligofructose or cellulose for 6 weeks following a 2-week run-in. Subjective appetite and side effect scores, breath hydrogen, serum short chain fatty acids (SCFAs), plasma gut hormones, glucose and insulin concentrations, EI, BW and adiposity were quantified at baseline and post-supplementation. RESULTS: Oligofructose increased breath hydrogen (P < 0.0001), late acetate concentrations (P = 0.024), tended to increase total area under the curve (tAUC)420 mins peptide YY (PYY) (P = 0.056) and reduced tAUC450 mins hunger (P = 0.034) and motivation to eat (P = 0.013) when compared with cellulose. However, there was no significant difference between the groups in other parameters although within group analyses showed an increase in glucagon-like peptide 1 (GLP-1) (P = 0.006) in the cellulose group and a decrease in EI during ad libitum meal in both groups. CONCLUSIONS: Oligofructose increased plasma PYY concentrations and suppressed appetite, while cellulose increased GLP-1 concentrations. EI decreased in both groups. However, these positive effects did not translate into changes in BW or adiposity.
Asunto(s)
Adiposidad/efectos de los fármacos , Regulación del Apetito/efectos de los fármacos , Suplementos Dietéticos , Péptido 1 Similar al Glucagón/sangre , Oligosacáridos/administración & dosificación , Péptido YY/sangre , Adulto , Apetito/efectos de los fármacos , Área Bajo la Curva , Glucemia/metabolismo , Peso Corporal , Celulosa/administración & dosificación , Fibras de la Dieta/administración & dosificación , Ingestión de Energía/efectos de los fármacos , Ácidos Grasos/sangre , Femenino , Voluntarios Sanos , Humanos , Insulina/sangre , Masculino , Persona de Mediana Edad , Obesidad/metabolismo , Sobrepeso/metabolismo , Cooperación del Paciente , Método Simple Ciego , Adulto JovenRESUMEN
OBJECTIVES: Roux-en-Y gastric bypass (RYGB) has greater efficacy for weight loss in obese patients than gastric banding (BAND) surgery. We hypothesise that this may result from different effects on food hedonics via physiological changes secondary to distinct gut anatomy manipulations. DESIGN: We used functional MRI, eating behaviour and hormonal phenotyping to compare body mass index (BMI)-matched unoperated controls and patients after RYGB and BAND surgery for obesity. RESULTS: Obese patients after RYGB had lower brain-hedonic responses to food than patients after BAND surgery. RYGB patients had lower activation than BAND patients in brain reward systems, particularly to high-calorie foods, including the orbitofrontal cortex, amygdala, caudate nucleus, nucleus accumbens and hippocampus. This was associated with lower palatability and appeal of high-calorie foods and healthier eating behaviour, including less fat intake, in RYGB compared with BAND patients and/or BMI-matched unoperated controls. These differences were not explicable by differences in hunger or psychological traits between the surgical groups, but anorexigenic plasma gut hormones (GLP-1 and PYY), plasma bile acids and symptoms of dumping syndrome were increased in RYGB patients. CONCLUSIONS: The identification of these differences in food hedonic responses as a result of altered gut anatomy/physiology provides a novel explanation for the more favourable long-term weight loss seen after RYGB than after BAND surgery, highlighting the importance of the gut-brain axis in the control of reward-based eating behaviour.