Mitochondrial bioenergetic pathways in blood leukocyte transcriptome decrease after intensive weight loss but are rescued following weight regain in female physique athletes

Prolonged periods of energy deficit leading to weight loss induce metabolic adaptations resulting in reduced expenditure, but the mechanisms for conservation are incompletely understood. We examined 42 healthy athletic females (age 27.5 ± 4.0 years, body mass index 23.4 1.7 kg/m2) who volunteered into either a group dieting physique competition (n = 25) or control 17). The diet substantially their intake and moderately increased exercise levels fat that was regained during voluntary regain period. maintained typical lifestyle habits as instructed. From group, fasting blood samples were drawn at baseline (PRE), after 4- 5-month (PRE-MID), (MID-POST) well from similar intervals. Blood analyzed determine leukocyte transcriptome by RNA-Sequencing serum metabolome nuclear magnetic resonance (NMR) platform. intensive period induced several adaptations, including prominent suppression transcriptomic signature mitochondrial OXPHOS ribosome biogenesis. upstream regulator analysis suggested this reprogramming cellular metabolism may be mediated via AMPK/PGC1-? signaling mTOR/eIF2 signaling-dependent pathways. Our findings show first time prolonged deprivation modulation can observed through minimally invasive measures systemic level, suggesting adaptation is broader humans than previously thought.