When people with excess body fat eat very few carbs and more fats, their bodies burn more fat for fuel during intense exercise, as shown by lower respiratory exchange ratio measurements.
Scientific Claim
Very low-carbohydrate high-fat diets significantly reduce respiratory exchange ratio (RER) during maximal exercise in overfat adults, indicating increased fat oxidation.
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The study directly measured RERpeak and found significant decreases in VLCHF groups, which is appropriately described as indicating increased fat oxidation. The causal language is appropriate for this specific physiological measurement.
Source Excerpt
“RERpeak significantly decreased in the VLCHF and VLCHF+HIIT groups, as was shown in our previous studies. This indicates an increased rate of fat oxidation.”
Evidence from Studies
Supporting Evidence (1)
The RCT design shows statistically significant decreases in RERpeak specifically in VLCHF groups compared to HIIT and control groups. The study measured RER using breath-by-breath gas analysis, which is a reliable method for assessing substrate utilization during exercise.