None listed
Conditions
Brief summary
To evaluate the hypotheses: (i) that both oral and small intestinal exposure to oleic acid (C18:1) will modulate antropyloroduodenal pressures, gut peptide, OEA and serum triglyceride responses, and suppress energy intake (ii) that combined oral and small intestinal exposure to oleic acid will interact to enhance the stimulation of antropyloroduodenal pressures, gut peptide, OEA and serum triglyceride responses, and suppression of energy intake, when compared with either oral or small intestinal infusion alone, and (iii) that these effects will occur in “tasters”, but not “non-tasters”, of oleic acid.
Interventions
Participants will undergo sensory testing to determine whether or not they are sensitive to the taste of the free fatty acid, oleic acid, in a milk-based drink. They will be asked to taste and rate solutions with and without oleic acid, those who correctly identify the solution containing oleic acid on three occasions will be classed as tasters, those who do not taste it, or rate it incorrectly more than once will be classified as non-tasters. Following categorization into either the “taster”,
Participants will undergo sensory testing to determine whether or not they are sensitive to the taste of the free fatty acid, oleic acid, in a milk-based drink. They will be asked to taste and rate solutions with and without oleic acid, those who correctly identify the solution containing oleic acid on three occasions will be classed as tasters, those who do not taste it, or rate it incorrectly more than once will be classified as non-tasters. Following categorization into either the “taster”, or “non-taster”, group, each participant will be studied on four occasions, separated by at least 7 days, to evaluate the effects of: (i)oral exposure to a non-fat milk-based beverage with 1.8 mM oleic acid (C18:1) (10 ml samples at 3 minute intervals for 20 minutes)combined with a 90 minute intraduodenal infusion of C18:1 (participants will be intubated with an nasoduodenal catheter through which the infusion will be administered at a rate of 2 ml/min, 0.76 kcal/min) (ii)oral exposure to a non-fat milk-based beverage without C18:1 combined with intraduodenal infusion of C18:1 (iii)oral exposure to a non-fat milk-based beverage with 1.8 mM C18:1 combined with intraduodenal infusion of control (0.9 % saline) (iv)oral exposure to a non-fat milk-based beverage without C18:1 combined with intraduodenal infusion of control (0.9 % saline)
Sponsors
Dr Tanya Little
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Prevention
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
18 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
Equal numbers of healthy male and female subjects, 15 of normal body weight for their height (body mass index (BMI): 19 - 25 kg/m2), and 15 obese (BMI 30 – 35 kg/m2), aged 18-55 years. Subjects will need to be unrestrained eaters, non-smokers, and for female subjects will be required to be taking an appropriate hormonal contraceptive.
Exclusion criteria
(1)significant gastrointestinal symptoms; disease or surgery (2)current use of prescribed or non-prescribed medications (including vitamins and herbal supplements) which may affect energy metabolism, GI function, body weight or appetite (e.g. domperidone and cisapride, anticholinergic drugs (e.g. atropine), metoclopramide, erythromycin, hyoscine, orlistat, green tea extracts, Astragalus, St John's Wort etc.) (3)diabetes mellitus (4)epilepsy (5)cardiovascular or respiratory disease (6)any other significant illness as assessed by the investigator (7)allergy to local anaesthetic (8)intake of > 20 g alcohol on a daily basis (9)smokers (cigarettes, cigars, marijuana) (10)in female subjects, pregnancy or lactation. A pregnancy test will be performed in all female subjects, using a urine sample, prior to commencement of the study and subsequently prior to each study day (11)restrained eaters, as determined by a score of >12 on the eating restraint questionnaire component of the eating questionnaire (35). However, while the degree of eating restraint will be assessed and recorded in the obese subjects, this will not be used as an exclusion criteria, as the majority of obese subjects are likely to have some degree of eating restraint. (12)donation of blood in the 12 weeks prior to enrolment in the study. Subjects will also be instructed to abstain from donating blood for 12 weeks after study completion (13)low iron levels (14)consumption of a vegetarian diet
Outcome results
None listed