The Effects of Energy Imbalance on Food Intake Behaviors

Study Overview
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Brief Summary
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This study will determine whether changes in energy balance alter regional neuronal activation of brain regions associated with food intake in individuals screened to be either resistant or prone to obesity. Specifically, it will determine whether foods of hedonic value elicit changes in regional neuronal activity in the fasted and fed state in obese-resistant and obese-prone men and women in varying states of energy balance.

Official Title
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The Effects of Energy Imbalance on Food Intake Behaviors

Conditions
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Obesity

Intervention / Treatment
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* Other: Eucaloric Feeding Period
* Other: Overfeeding Feeding Period
* Other: Underfeeding Feeding Period


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: In the obese-prone group: BMI between 20-30 Report at least one obese first-degree relative Self-describe as struggling with weight Weight-stable for at least 3 months prior to study participation In the obese-resistant group: BMI between 17-25 Report no obese first-degree relatives Self-describe as naturally thin and have never been overweight Overall weight stability Exclusion Criteria: Significant medical or psychiatric disease History of eating disorder Left handed Unable to complete an MRI scan (e.g., metal in body, claustrophobic)

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Eucaloric<br>Participants will consume a eucaloric diet with a macronutrient composition of 20% protein, 30% fat and 50% carbohydrate for 4 days (Eucaloric Feeding Period). The caloric value of the diet will be calculated based on lean body mass plus an activity factor to ensure energy and macronutrient balance. | Other: Eucaloric Feeding Period<br> <br> |
| Experimental: Overfed<br>Following 3 days of eucaloric feeding, participants will complete a 1-day overfeeding period (Overfeeding Feeding Period), during which their diet will have a daily energy value of 40% greater than the eucaloric diet (Eucaloric Arm), although the macronutrient composition will remain the same (20% protein, 30% fat, 50% carbohydrate). | Other: Overfeeding Feeding Period<br> <br> |
| Experimental: Underfed<br>Following 3 days of eucaloric feeding, participants will complete a 1-day underfeeding period (Underfeeding Feeding Period), during which their diet will have a daily energy value of 40% less than the eucaloric diet (Eucaloric Arm), although the macronutrient composition will remain the same (20% protein, 30% fat, 50% carbohydrate). | Other: Underfeeding Feeding Period<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in neuronal response to food vs. nonfood objects in fasted vs. fed states | Change in neuronal response to food vs. nonfood objects in the overfed and underfed feeding periods as compared to the eucaloric period between fasted and fed states in obese-prone as compared to obese-resistant individuals. | Day 5 of each of the three 5-day study periods (Eucaloric, Overfeeding, Underfeeding) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in appetite ratings | Change in appetite ratings via visual analog scale (VAS; 0-100) before vs. after a meal in the overfeeding and underfeeding periods compared to the eucaloric feeding periods between obese-resistant and obese-prone individuals. | At baseline, in the fasted state on Day 5 of each of the three 5-day study periods (Eucaloric, Overfeeding, Underfeeding) and at 30, 90, 120, 150 and 180 minutes after a meal on Day 5 of each of the three 5-day study periods. | 
| Change in food cravings | Change in food cravings (questionnaire) before vs. after a meal in the overfeeding and underfeeding periods compared to the eucaloric feeding periods between obese-resistant and obese-prone individuals. | At baseline and both before and after a meal on Day 5 of each of the three 5-day study periods (Eucaloric, Overfeeding, Underfeeding). | 
| Change in leptin levels | Change in blood leptin levels before vs. after a meal in the overfeeding and underfeeding periods compared to the eucaloric feeding periods between obese-resistant and obese-prone individuals. | At baseline, in the fasted state on Day 5 of each of the three 5-day study periods (Eucaloric, Overfeeding, Underfeeding) and at 30, 90, 120, 150 and 180 minutes after a meal on Day 5 of each of the three 5-day study periods. | 
| Change in ghrelin levels | Change in blood ghrelin levels before vs. after a meal in the overfeeding and underfeeding periods compared to the eucaloric feeding periods between obese-resistant and obese-prone individuals. | At baseline, in the fasted state on Day 5 of each of the three 5-day study periods (Eucaloric, Overfeeding, Underfeeding) and at 30, 90, 120, 150 and 180 minutes after a meal on Day 5 of each of the three 5-day study periods. | 
| Change in PYY levels | Change in blood Peptide YY (PYY) levels before vs. after a meal in the overfeeding and underfeeding periods compared to the eucaloric feeding periods between obese-resistant and obese-prone individuals. | At baseline, in the fasted state on Day 5 of each of the three 5-day study periods (Eucaloric, Overfeeding, Underfeeding) and at 30, 90, 120, 150 and 180 minutes after a meal on Day 5 of each of the three 5-day study periods. | 
| Change in neuronal response to hedonic vs. basic food images | Change in neuronal response to hedonic vs. basic food images in the overfed and underfed feeding periods as compared to the eucaloric period between fasted and fed states in obese-prone as compared to obese-resistant individuals. | Day 5 of each of the three 5-day study periods (Eucaloric, Overfeeding, Underfeeding) | 
| Change in body weight | Change in body weight from baseline for up to 5 years in obese-resistant and obese-prone individuals | Baseline and every 6 months for up to 5 years after study participation. |