Olfaction, Diet, Exercise, Energy Depletion, Food Hedonics, Food Reward
Conditions
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.
Interventions
25% Energy Depletion by Diet only for 3 Days
25% Energy Depletion by Exercise only for 3 Days
Sponsors
Study design
Eligibility
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Ad Libitum Energy Intake at Buffet Lunch--total kcals consumed at lunch meal measured to nearest 0.5grams. | Day 1 and Day 4 of each study arm (DIET and EX) | Ad libitum measure of energy intake at lunch time at Day 1 and Day 4 of study |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Relative-Reinforcing Value of Food as measured by food points earned during a computerized behavioral choice tast | Day 1 and Day 4 of each study arm (DIET and EX) | Computer task measuring reinforcing value of preferred snack food and preferred fruit at Day 1 and Day 4 of study |
| Olfaction--Odor Detection Threshold measured by Sniffin Sticks odorized pens | Day 1 and Day 4 of each study arm (DIET and EX) | Measure of odour threshold for n-butanol taken at Day 1 and Day 4 of study |
| Change in fasting measure of Leptin | Day 1 and Day 4 of each study arm (DIET and EX) | One fasting sample of plasma Leptin |
| Change in fasting measure of Ghrelin | Day 1 and Day 4 of each study arm (DIET and EX) | One fasting sample of plasma Ghrelin taken at Day 1 and Day 4 of study |