Energy Expenditure From ECAL Indirect Calorimeter in a Multicomponent Weight Management Service
Condition: Obesity; Severe Obesity; Sleep Apnoea
MeSH terms: Obesity; Obesity, Morbid
Study type: Interventional

Summary: 
      Whether greater weight loss is as a result of a smaller reduction in energy expenditure with
      caloric restriction is not known. Resting energy expenditure and 24-hour energy expenditure
      vary substantially between individuals. In some cases, relatively reduced rates of 24h EE
      predict weight gain in some populations who have high prevalence of obesity. Obese
      individuals that lose weight experience a decrease in 24-h EE and resting energy expenditure
      that is lower than predicted based on changes in body composition. Most weight loss studies
      have found a large individual variation in the amount of weight change, and whether an
      individual's response to an intervention can be predicted is not clear. Measurements of
      24-hour EE in response to fasting may help predict weight loss. The ECAL indirect calorimeter
      (ECAL) is a validated device purpose-built to provide the practitioner and patient with
      energy information that allows for more accurate, reliable method of establishing an obese
      individuals' metabolic profile. The aim of this study is to determine whether providing
      energy information from ECAL indirect calorimeter as an adjunct to the multicomponent weight
      management intervention in non-diabetic obese and severely obese individuals would help
      predict the response of weight loss.
    

Detailed description: 
      Weight loss is important to improve overall health and reduce risk of obesity-related
      comorbidities such as diabetes. Numerous studies performed on individuals with predisposed
      genetic propensity to obesity who are deemed to be metabolically 'thrifty', require further
      structured intensification of caloric restriction and change in physical activity in order to
      achieve weight loss. Whether greater weight loss is as a result of smaller reduction in
      energy expenditure with calorie restriction is not known. Resting energy expenditure and
      24-hour energy expenditure vary substantially between individuals. Obese individuals that
      lose weight experience a decrease in 24-h EE and resting energy expenditure that is lower
      than predicted based on changes in body composition. Most weight loss studies have found a
      large individual variation in the amount of weight change, and whether an individual's
      response to an intervention can be predicted is not clear. Measurements of 24-hour EE in
      response to fasting may help predict weight loss. The ECAL indirect calorimeter (ECAL) is a
      validated device purpose-built to provide the practitioner and patient with energy
      information that allows for more accurate, reliable method of establishing an obese
      individuals' metabolic profile. The ECAL device also measures the respiratory quotient (RQ)
      which is the ratio of the volume of carbon dioxide expired to that of oxygen consumed by the
      individual for every breath. Previous studies demonstrated variability in role of RQ in
      predicting weight loss, but individuals who demonstrated an RQ in the lower range (<0.72)
      were more likely to maintain the weight-loss achieved on a caloric restriction and avoid a
      weight loss rebound as compared to those with RQ in the higher range (>0.75). This suggests
      that RQ could prove useful in clinical practice as a prognostic marker for long-term
      effectiveness of low- and very-low-calorie diets used to induce weight loss. Baltimore
      Longitudinal Study on Aging shared a similar finding that fasting RQ or respiratory exchange
      ratio adjusted for age, BMI, and fat free mass was positively related to weight change. The
      aim of this study is to determine whether providing energy information from ECAL indirect
      calorimeter as an adjunct to the multicomponent weight management intervention in
      non-diabetic obese and severely obese individuals would help predict the response of weight
      loss.
    

Intervention name(s): ECAL Indirect Calorimeter; Diet, exercise & behaviour modification therapy
Intervention type(s): Device; Behavioral
Intervention description(s): The ECAL is an open-circuit portable indirect calorimeter that measures both volume of CO2 expired and O2 consumed using a small mixing chamber. Participants will breathe through a mouthpiece with a nose clip applied whilst lying in a restful and comfortable position for 15 minutes. ECAL device will provide breath-by-breath measurements of the resting energy expenditure and respiratory quotient which will allow both practitioners and participants to monitor their metabolic health and compare the effect of dietary and physical activity intervention over the course of the structured intensive lifestyle intervention (24-weeks).; Standard care (SC) - participants receive standard care (diet, exercise & behaviour modification therapy) as part of the multicomponent weight management intervention within the tier 3 weight management service. Practitioners will rely on standard predictive equations to provide dietary advice and intervention.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Parallel assignment
Masking: Double (Participant, Care Provider)
Primary purpose: Treatment
Keywords: weight management; obesity; severe obesity; structured dietary intervention; calorie restriction; indirect calorimetry; resting energy expenditure; resting metabolic rate; respiratory quotient; substrate oxidation; glycemic variability; insulin sensitivity; peripheral neuropathy