BDNF	Brain-Derived Neurotrophic Factor
IF	Intermittent Fasting
TRE	Time-Restricted Eating
ADF	Alternate-Day Fasting
RRF	Religious/Ritual Fasting
BHB	β-Hydroxybutyrate
HPA	Hypothalamic–Pituitary–Adrenal (axis)
HCA2	Hydroxycarboxylic Acid Receptor 2 (HCAR2; GPR109A)
AMPK	AMP-Activated Protein Kinase
TNF-α	Tumor Necrosis Factor-Alpha
IL-6	Interleukin-6
RCT	Randomized Controlled Trial
MDD	Major Depressive Disorder
HDRS-17	17-Item Hamilton Depression Rating Scale
STAI-S	State-Trait Anxiety Inventory-State subscale
PPF	Periodic Prolonged Fasting
IL6	Interleukin-6
TNFα	Tumor Necrosis Factor-Alpha
ATP	Adenosine Triphosphate
IL1β	Interleukin-1 Beta
H3	Histone H3
PGC1α	Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-Alpha
GABA	Gamma-Aminobutyric Acid
ULK1	Unc-51-Like Autophagy-Activating Kinase 1
ACTH	Adrenocorticotropic Hormone
NF-κB	Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells
PRISMA	Preferred Reporting Items for Systematic Reviews and Meta-Analyses
ED	Eating Disorder
CREB-PGC	cAMP Response Element-Binding Protein–PGC-1 Axis
NLRP3	NOD-, LRR- and Pyrin Domain-Containing Protein 3 (Inflammasome)
IL-1β	Interleukin-1 Beta
REM	Rapid Eye Movement
NMDA	N-Methyl-D-Aspartate
TRF	Time-Restricted Feeding
HRV	Heart-Rate Variability
FMD	Fasting-Mimicking Diet
PTSD	Post-Traumatic Stress Disorder
CAPS-5	Clinician-Administered PTSD Scale for DSM-5
BMI	Body Mass Index
CNS	Central Nervous System.
PGC-1α	Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-Alpha