Modulating Appetite in Overweight Women

INTERVENTION: The study is to determine the effectiveness of a natural dietary bitter plant extract at suppressing appetite and food intake in overweight females. The three treatment arms comprise an acute intervention of a single delayed release capsule containing either a high (250 mg) or low (100 mg) dose of a super‐critical CO2 extract of hops (Humulus lupulus) compared with placebo (vehicle control) provided 1 hour before a standard breakfast (1.5 MJ) provided at 9am. A minimum of a 3 day washout period will then follow where participants revert to their normal diet before entering the next treatment arm of the study. CONDITION: Obesity PRIMARY OUTCOME: Energy intake at the ad libitum lunch of ham and cheese sandwiches will be measured by double weighing all components of the meal before and after the meal is completed. Energy intake will be calculated using the nutritional analysis software FoodWorks 7 (Xyris Software, Ausralia). Macronutrient intake at the ad libitum lunch of ham and cheese sandwiches will be measured by double weighing all components of the meal before and after the meal is completed. Macronutrient intake will be calculated using the nutritional analysis software FoodWorks 7 (Xyris Software, Ausralia). ; 1. Extremely alert ; 2. Very alert ; 3. Alert ; 4. Rather alert ; 5. Neither alert or sleepy ; 6. Some signs of sleepiness ; 7. Sleepy, but no effort to keep awake ; 8. Sleepy, some effort to keep awake ; 9. Very sleepy, great effort to keep awake, fighting sleep INCLUSION CRITERIA: • Female • Aged 18‐50 years • Being overweight or obese as determined by a Body Mass Index greater than or equal to 25 kg/m2 and less than or equal to 35 kg/m2 • A waist‐hip ratio of greater than 0.8 • Normal menstrual cycle • Normal gross gastrointestinal tract anatomy, as ascertained by self‐report • Regular pattern of meal consumption (breakfast, lunch and dinner) as determined by self‐report. • Generally healthy, as ascertained by self‐report SECONDARY OUTCOME: Between meal subjective ratings of Nausea will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling to the question “How nauseas do you feel?" anchored by “Not at all” to “Extremely nauseas”. Between meal subjective ratings of Prospective food consumption will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling to the question “How much do you think you can eat?” anchored with “Nothing at all” to “A large amount” Between meal subjective ratings of fullness will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling to the question “How full do you feel?” anchored with “Not full at all” to “totally full” Between meal subjective ratings of hunger will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling to the question “How hungry do you feel?” anchored with “Not hungry at all” to “Never been more hungry” Between meal subjective ratings of satiety will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling to the question “How satisfied do you feel?” anchored by “completely empty” to “cannot eat another bite”. Between meal subjective ratings of the desire to eat will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling to the question “How strong is your desire to eat?” anchored with “Very weak” to “Very strong Between meal subjective ratings of thirst will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling to the question "How thirsty do you feel right now?” anchored by “Not thirsty at all” to “Extremely thirsty” Between meal subjective ratings of tiredness will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling to the question "How tired do you feel?” anchored by “Not at all” to “Extremely tired”. Changes in tiredness will also be assessed using the Karolinska Sleepiness Scale, a measure of situational sleepiness using a nine point scale to measure the subjective level of sleepiness at a particular times of day. Participants indicate which level descriptor best reflects the psycho‐physical sate experienced in the last 10 min. The descriptors and values are : ; Gastrointestinal discomfort will be assessed using a computerised questionnaire adapted from a validated assessment tool (Bovenschen et al. 2006) with some modification (Yuan et al. 2014). Factors evaluated are abdominal pain, epigastric pain, heartburn, regurgitation, abdominal rumbling, bloating, nausea, vomiting, belching, and flatulence measured on a computerised 100 mm visual analogue scales (VAS) anchored with the terms “none” and “unbearable”. Stool consistency will also be reported over 24 h in accordance with the Bristol Stool Scale (Lewis & Heaton 1997) Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling for the criteria "aftertaste" anchored by “Much" to "None”. Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling for the criteria "pleasantness" anchored by “Good” to “Bad”. Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling for the criteria "smell" anchored by “Good” to “Bad”. Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling for the criteria "taste" anchored by “Good” to “Bad”. Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling for the criteria "visual appeal" anchored by “Good” to “Bad”. Subjective ratings of meal palatability will be collected using computerised 100 mm visual analogue scales. Participants will mark their responses by placing the cursor on the 100‐mm scale according to their subjective feeling for the criteria overall palatability anchored by “Good” to “Bad”. The time of day of all bowel movements (stool frequency) will be recorded for 24 h post treatment.