Keywords: سلولهای آلوئولار; AT2; alveolar type-2; BALT; bronchus-associated lymphoid tissues; CR; Calorie restriction; CFE; colony forming efficiency; H&E; hematoxylin and eosin; HFD; High fat diet, used as (HF) in figures and table 7; LNEP; lineage negative epithelial progenitor; L