The Effects of Acute Caloric Deprivation on Odour Identification and Food Reward

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to determine how the modality of energy depletion can differently impact appetite hormones, ad libitum food intake, food hedonics, and olfaction.

Detailed Description
-----------------
The objectives of the current randomized controlled study were to examine how the modality of an acute 3 day isocaloric -25% energy depletion by dieting alone or by aerobic exercise alone differently impacts appetite and appetite-related hormones, ad libitum energy intake (EI), food hedonics and food reward, and olfaction. It was hypothesized that independent of modality of depletion, that relative to the control, there would be increased ad libitum feeding and food reward, improvements in smell performance, and a decline in fasting leptin and increase in fasting total ghrelin. It was also hypothesized that the increased food reward would prove to be a predictor of ad libitum EI and that relative to the depletion by aerobic exercise alone, the depletion by diet alone would produce greater compensatory increases in appetite, ad libitum EI, and food reward. Statistics To test for differences in body weight, plasma hormone concentrations, relative-reinforcing value of food (RRVF), and olfaction across each condition of the study, repeated measures ANOVA controlling for day 1 as a covariate was employed. Pairwise comparisons at day 4 using Sidak adjustment to account for multiple comparisons are reported when the ANOVA was significant. One way repeated measures ANOVAs with Sidak adjustments for multiple comparisons were used to test for differences in variables measured only at day 4: body composition (fat mas, %Fat, and fat free mass), appetite, palatability, and ad libitum EI.

Official Title
-----------------
The Effects of Acute Caloric Deprivation on Odour Identification and Food Reward

Conditions
-----------------
Olfaction, Diet, Exercise, Energy Depletion, Food Hedonics, Food Reward

Intervention / Treatment
-----------------
* Behavioral: DIET
* Behavioral: EX


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Free from any illness that could influence outcome of the experiment Weight-stable for >6months aged between 18-40 years Exclusion Criteria: diabetic smoker medication
Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: DIET ARM<br>A 25% energy depletion (daily for 3 days) induced by reducing the amount of energy intake that would otherwise keep the individual in energy balance. | Behavioral: DIET<br>* 25% Energy Depletion by Diet only for 3 Days<br>|
| Active Comparator: EX ARM<br>A 25% energy depletion (daily for 3 days) induced by performing aerobic exercise at 50% of V02max. | Behavioral: EX<br>* 25% Energy Depletion by Exercise only for 3 Days<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Ad Libitum Energy Intake at Buffet Lunch--total kcals consumed at lunch meal measured to nearest 0.5grams. | Ad libitum measure of energy intake at lunch time at Day 1 and Day 4 of study | Day 1 and Day 4 of each study arm (DIET and EX) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in fasting measure of Leptin | One fasting sample of plasma Leptin | Day 1 and Day 4 of each study arm (DIET and EX) | 
| Change in fasting measure of Ghrelin | One fasting sample of plasma Ghrelin taken at Day 1 and Day 4 of study | Day 1 and Day 4 of each study arm (DIET and EX) | 
| Change in Relative-Reinforcing Value of Food as measured by food points earned during a computerized behavioral choice tast | Computer task measuring reinforcing value of preferred snack food and preferred fruit at Day 1 and Day 4 of study | Day 1 and Day 4 of each study arm (DIET and EX) | 
| Olfaction--Odor Detection Threshold measured by Sniffin Sticks odorized pens | Measure of odour threshold for n-butanol taken at Day 1 and Day 4 of study | Day 1 and Day 4 of each study arm (DIET and EX) |