Research
Energy balance
Low energy availability reduces resting metabolic rate (RMR) by approximately 8% as an energy-conserving mechanism, independent of changes in body composition.
If you are training heavily and eating very little, your body may slow down its baseline calorie burn to survive. This is a normal adaptation, not a broken metabolism. Restoring adequate energy intake will help normalize your metabolic rate.
GoodSupportsHIGH confidence
RMR was 8% lower in the low EI (low EA) group, suggesting an energy conserving mechanism for maintenance of BMI and bodily function (Thompson et al., 1993).
Why this rating
Supported by multiple studies comparing low vs. adequate EA groups.
Source
Endocrine Effects of Relative Energy Deficiency in Sport
Kirsty J. Elliott‐Sale et al. · International Journal of Sport Nutrition and Exercise Metabolism · 2018
DOI 10.1123/ijsnem.2018-0127
narrative_reviewCited 219×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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