Use of Indirect Calorimetry in Obesity

Study Overview
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Brief Summary
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The investigators will retrospectively analyze and compare data of 2 groups of overweight and obese patients: subjects who followed a diet based on Resting Energy Expenditure (REE) measured by indirect calorimetry and subjects who followed a diet based on REE estimated by the Harris-Benedict equation. Propensity score adjustment will be used to adjust for known differences between the 2 groups

Official Title
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Use of Indirect Calorimetry in Dietary Setting in Obese Subjects: Retrospective Observational Study

Conditions
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Metabolism Disorder, Overweight and Obesity

Intervention / Treatment
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* Diagnostic Test: Indirect calorimetry


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI >25 Age ranging from 20 to 86 years Exclusion Criteria: BMI<25 Age <20 Age >86

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 86 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Indirect Calorimetry group (IC group)<br>Group who performed indirect calorimetry. REE measured by indirect calorimetry. | Diagnostic Test: Indirect calorimetry<br>* Indirect calorimetry will be performed by using an open-circuit calorimeter (Sensor Medics, Italy). Indirect calorimetry is the reference method for energy expenditure determination. A canopy hood covered the patient's head and expired air is extracted by a pump to be analyzed by metabolic cart sensors; flow rate is directly measured with a digital turbine flowmeter. After an overnight fast, patients will asked to lay supine in complete physical rest, not sleeping or talking for approximately 20-25 minutes, at a room temperature ranged between 22 and 24°C. The mean REE for each participant considers the last 15-20 minutes of measurements corresponding to steady state. Software of calorimeter will be set for minute-by-minute reading report of VO2 (Oxygen flow) and VCO2 (Carbon dioxide flow) measurement. Parameters obtained by Indirect Calorimetry will be the Resting Energy Expenditure and the Respiratory Quotient (RQ)<br>|
| NO Indirect Calorimetry group (NO-IC group)<br>Group who did not perform indirect calorimetry. Resting Energy Expenditure calculated by Harris-Benedict formula | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weight in Indirect Calorimetry group and in NO Indirect Calorimetry group | To compare body weight variation (kg) in two groups of overweight or obese patients: subjects who followed a diet formulated on REE measured by IC (IC group) and subjects who followed a diet based on REE predicted by the Harris-Benedict formula (NO-IC group) | 18 months | 
| BMI in Indirect Calorimetry group and in NO Indirect Calorimetry | To compare BMI variation (kg/m^2) in two groups of overweight or obese patients: subjects who followed a diet formulated on REE measured by IC (IC group) and subjects who followed a diet based on REE predicted by the Harris-Benedict formula (NO-IC group) | 18 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weight in male/female in Indirect Calorimetry group and in NO indirect Calorimetry group | To identify gender differences in weight variation (kg) between IC and NO-IC groups | 18 months | 
| BMI in male/female in Indirect Calorimetry group and in NO indirect | To identify gender differences in BMI variation (kg/m^2) between IC and NO-IC groups | 18 months |