The Effect of Beverages Varying in Protein Quantity on Appetite and Energy Intake

Lund University36 enrolled

Overview

Over the last decades, changes in the diet and lifestyle have led to overall energy imbalance becoming commonplace and the emergence of an obesity epidemic with more than 1.6 billion adults being overweight. Consumption of foods that can affect appetite by increasing satiety could regulate the total energy intake and thus body weight. There is data suggesting that the macronutrient composition of the foods and especially protein content may have a potent role on satiety. However, it is difficult to pinpoint the optimum quantity needed to observe significant effects of protein on satiety. The research project is dedicated to identify which food components \[proteins, carbohydrates (CHO), fats\] and the optimized protein quantity needed to accelerate satiation, suppress appetite and extend satiety until hunger appears again. It is hypothesized that the consumption of protein-enriched meals will induce a reduction in hunger through the impact on gut hormones and peptides that are closely related to the short-term regulation of food intake.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Enrollment

Conditions

Obesity

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 50 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Healthy males and females * Age range 18-50 years * Normal weight and overweight people as classified by BMI:22-27.9 kg/m2 (inclusive). * Weight stable (within 3 kg) two months prior to study inclusion * Understanding English well and feeling comfortable speaking it Exclusion Criteria: * Dietary protein consumption \>25% energy from protein * Had surgery in the previous 12 months * Have suffered a myocardial infarction or stroke at any time * Suffer from any blood-clotting disorder or prescription of any medication affecting blood clotting * Suffer from any metabolic disorders (e.g. diabetes, metabolic syndrome or hypertension) * Any requirement to take long-term medication, especially those active on the gastro-intestinal tract or for cardio-vascular disease * Any dietary restrictions or recently/currently on a weight reducing diet * Irregular eating patterns or not regularly consuming breakfast * Food allergies (e.g. milk protein allergies) or intolerances (e.g. lactose) * Use of medication which affects food intake or behaviour (e.g. anti-depressants) * Use of medication likely to affect taste, smell or appetite * Eating restraint based on the three Factor Eating Questionnaire * Use of any protein supplements * A history of alcohol or drug misuse (the average daily number of units of alcohol considered as acceptable is 2-3 units women; 3-4 units men * Smoking * Athletes in training (\>10 h exercise/week) * Female that is breast-feeding, pregnant, or if of child-bearing potential and are not using effective contraceptive precautions * Involvement in a study involving an experimental drug/medication within 3 months prior to entry of this study * Blood pressure \> 160/90 mmHg * Vegan or Vegetarian * Glucose \> 6 mmol/L * Gamma glutamyl transferase \> 1.9 μkat / L * Alanine transaminase \> 1.1 μkat / L * Cholesterol \> 6.5 mmol/L * Triglycerides \> 2.0 mmol/L

Outcomes

Primary Outcomes

Changes from baseline in perceived appetite and satiety

The appetite profile is assessed using validated Visual Analogue Scales (VAS) ratings (i.e hunger, fullness, desire to eat, prospective food consumption). The Questionnaires are performed electronically in personal laptops using the Adaptive Visual Analogue Scales (AVAS) software.

Time frame: Assessed every 30 min for 270 min after each of the seven beverages which are served at least one week apart (7 weeks)

Secondary Outcomes

Ad libitum energy intake

Energy intake is assessed by ad libitum hot pasta meal provided 210 min after the test beverages, which are given as breakfast. Subjects are instructed to eat only until they feel comfortable satisfied and are given 25min to consume the meal. The total energy consumed is monitored

Time frame: Energy intake is assessed 210 min after the 7 test beverages, which are served one week apart.

Changes from baseline in the postprandial concentration of satiety hormones

Blood samples (2 ml) are collected at 0 min (fasted blood sample), 30, 60, 90, 150 and 205 min (i.e. total of 6 samples) over the morning on each test day (separated by 1 week) to quantify the plasma concentrations of circulating appetite regulating hormones. Protease inhibitors are added to the samples to reduce protein degradation. All samples are centrifuged at 4 C for 10 min at 2000 g after collection and are separated and stored in cryogenic vials at -80 C.

Time frame: Assessed at 6 points in time over the morning of each of the 7 test days, which are separated by 1 week (7 weeks)

Hedonic ratings and palatability of the test beverages and meals

The palatability and hedonic ratings are assessed using validated Visual Analogue Scales (VAS) ratings (i.e appearance, taste, overall palatability). The Questionnaires are performed electronically in personal laptops using the Adaptive Visual Analogue Scales (AVAS) software.

Time frame: Assessed immediately after consumption of the 7 test beverages and pasta meal (7 weeks)

Changes from baseline in the postprandial concentration of glucose

Capillary blood samples are collected by finger-prick at 0 min (fasted blood sample), 30, 45, 60, 90, 150 and 205 min (i.e. total of 7 samples) over the morning on each test day (separated by 1 week) to quantify the glucose concentration using HemoCue Glucose System.

Time frame: Assessed at 7 points in time over the morning of each of the 7 test days, which are separated by 1 week (7 weeks)