Novel Approach to Assess Metabolic Flexibility in a Respiratory Chamber

Not Applicable

Completed

Conditions: Diabetes Mellitus, Type 2

Interventions: Other: High fat meal
Other: Low fat meal

Registration Number: NCT03839641

Lead Sponsor: Pennington Biomedical Research Center

Brief Summary: The overarching aim of this study: To determine the effect of different meal compositions (high- vs. low-fat) on metabolic flexibility as it relates to meal-stimulated change in respiratory quotient (ΔRQ1) and sleep (ΔRQ2) metabolic flexibility, as well as the time course changes in respiratory quotient, RQ (i.e., peak RQ, time to peak RQ, nadir RQ, time to nadir, slope).

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 10

Inclusion Criteria

Eligibility criteria include:
- Healthy male or female
- Ages 18-40 y
- BMI between 20 kg/m2 and 30 kg/m2 (±0.5 kg/m2 will be accepted)
- Are willing to consume pre-prepared meals
- Are willing to maintain current physical activity, sleep schedule, and dietary habits during the study.
- Medically cleared for participation in the study by Medical Investigator

Exclusion Criteria

Participants are ineligible to participate (or will be excluded from participating in this study) if they meet any of the following criteria:
- Unstable weight in the last 3 months [gain or loss >7 lb (or 3.2 kg)]
- Currently working shift work
- Smoking or use of tobacco products within the last 3 months
- Amenorrhea (or absence of regular monthly cycles)
- History of clinically diagnosed diabetes or a fasting blood glucose >126 mg/dL
- Average screening blood pressure >140/90 mmHg
- Previous bariatric surgery (or other surgeries) for obesity or weight loss
- Use of medications affecting metabolism or sleep
- History of neurological disease
- History of cardiovascular disease (or other chronic diseases)
- Pregnant, planning to become pregnant, or breastfeeding
- Adherence to special restrained diets (e.g., low-carbohydrate, low-fat, or vegetarian/vegan diets) over the last 3 months.

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
High Fat Meal Second	Low fat meal	Arm 2 participants randomized to receive low fat meal first, and high fat meal second
High Fat Meal Second	High fat meal	Arm 2 participants randomized to receive low fat meal first, and high fat meal second
High Fat Meal First	High fat meal	Arm 1 participants randomized to receive high fat meal first, and low fat meal second
High Fat Meal First	Low fat meal	Arm 1 participants randomized to receive high fat meal first, and low fat meal second

Primary Outcome Measures

Name	Time	Method
Overnight Respiratory Exchange Ratio	12 hours	12-h mean of respiratory exchange ratio following each meal type. measurement interval = 12h following start of meal (7pm) The respiratory exchange ratio refers to the proportion of macronutrients being oxidized. A respiratory exchange ratio value of 1.0 indicates only carbohydrates are being oxidized, while a ratio value of 0.7 indicates only fats are being oxidized. Intermediate values, such as 0.85, indicates that both carbohydrate and fats are being oxidized.

Secondary Outcome Measures

Name	Time	Method
Peak Increase in Respiratory Exchange Ratio	4 h	mean of peak increase in respiratory exchange ratio (Peak values - baseline values) following each meal type Peak values were defined as the peak respiratory exchange ratio value measured during the post-meal period, 6pm-10pm. Baseline values were measured 1h prior to meal (5:00-5:45pm) measurement interval of peak values= 4h (6pm-10pm) A larger value in this measurement indicates that more carbohydrate than fats were being oxidized as fuel during the measurement period.
Peak Decrease in Respiratory Exchange Ratio	12 h	mean of peak decrease in respiratory exchange ratio (baseline values -nadir values) following each meal type Peak values were defined as the peak respiratory exchange ratio value measured during the post-meal period, 6pm-10pm. Baseline values were measured 1h prior to meal (5:00-5:45pm) measurement interval of nadir values= 12h (6pm-6am) A larger value in this measurement indicates that more fats than carbohydrate were being oxidized as fuel during the measurement period.
Sleep Respiratory Exchange Ratio	3 h	mean of respiratory exchange ratio following each meal type during sleep period, 2am-5am., 2am-5am. measurement interval = 3h (2am-5am) The respiratory exchange ratio refers to the proportion of macronutrients being oxidized. A respiratory exchange ratio value of 1.0 indicates only carbohydrates are being oxidized, while a ratio value of 0.7 indicates only fats are being oxidized. Intermediate values, such as 0.85, indicates that both carbohydrate and fats are being oxidized.
Slope of Respiratory Exchange Ratio	12 h	This value indicates the speed and magnitude of the participants change in respiratory exchange ratio between the peak and nadir values. A more negative value in this measurement indicates either a short time interval between the highest and lowest respiratory exchange ratio values measured and/or a large difference between the highest and lowest values of respiratory exchange ratio values measured.
Time to Peak Respiratory Exchange Ratio	12 h	Average time from meal to peak respiratory exchange ratio value This measurement indicates how long on average it took form the onset of the meal, 6pm, for the participants to achieve their highest/peak respiratory exchange ratio value.
Time to Nadir Respiratory Exchange Ratio	12 h	Average time from meal to nadir respiratory exchange ratio value This measurement indicates how long on average it took form the onset of the meal, 6pm, for the participants to achieve their lowest/nadir respiratory exchange ratio value.