When you’re talking about long-term improvements in weight control and better management of chronic conditions such as diabetes and metabolic syndrome, a relatively ‘new kid’ on the block involves the clinical use of an Indirect Calorimeter (ECAL). It’s been around for while up in the stratosphere of the elite athlete but is now more widely available for the average punter.
ECAL measures O2 consumption and CO2 production and is a research standard for analysing whole-body energy expenditure. It also provides an index of the nature of macronutrient substrate oxidation, namely carbohydrate (CHO) versus fat oxidation. ECAL determines three key pieces of information relating to metabolic profile:
- Resting Metabolic Rate (RMR): the number of calories an individual requires at rest.
- Substrate Utilisation: the proportional use of fat or glucose to produce energy.
- Mitochondrial Efficiency: the optimisation of an individual’s mitochondria to extract and utilise oxygen to produce energy.
The real value in measuring individual metabolism is that it facilitates the implementation of change and, with subsequent retesting, the ability to gauge if that desired metabolic change is actually taking effect.
We’ve found that metabolic changes often occur before any significant alteration in weight or blood sugar levels.
Working with patients on an individual level allows us to identify factors supporting long-term weight management and improvements in overall health.
So, how does this approach differ from standard diet and exercise advice?
Most current dietary strategies focus on creating a negative energy balance. While this is important for weight loss, a majority of studies has shown poor long-term compliance and consistent reports of persistent hunger. Without the use of ECAL you’re just guessing at energy balance, and that’s less than ideal. An ability to measure Substrate Utilisation also allows improved optimisation of fat use and takes the guesswork out of weight management.
An ECAL approach involves personalised exercise and diet strategies, refined with regular testing, that aims to optimise an individual’s metabolism. For example, we may suggest dietary changes to increase fat utilisation thus decreasing the reliance on glucose to provide energy. We may also suggest exercise strategies to improve the cells’ ability to use oxygen, which might actually involve a program of less strenuous exercise.
The patient cohort that’s most likely to benefit from ECAL is one with a BMI of 30+, those with fatty liver disease and Type 2 Diabetes, women with PCOS and anyone considering bariatric surgery. Practitioners offering the ECAL program generally work with a patient for 12 weeks and the ultimate aim is a 5% weight loss (at least) over 12 weeks, which is clinically significant in terms of diabetes management, improved fertility and sleep apnoea.
Every patient has a unique metabolic profile and a personalised clinical intervention such as ECAL aims to normalise A1c levels and, in returning them to a pre-diabetic range, allow an individual to be medication-free.
References available on request.