(A) Kaplan-Meier survival curves for mice fed a standard diet (SD) or SD supplemented with low dose or high dose of NAM (n = 100/group).

(B) Kaplan-Meier survival curves for mice fed a high-fat diet (HFD) or HFD supplemented with either low dose or high dose of NAM (n = 100/group).

(C and D) Body weight trajectories over the course of the study.

(E) Timetable for the measure of various outcomes during the treatment protocol.

(F and G) Oral glucose tolerance test. Inset: area under the curve (AUC) (n = 6/group).

(H–J) After 49 weeks of treatment, mice were placed into metabolic cages to measure the respiratory exchange ratio (RER) as detailed in the STAR Methods , n = 6/group.

(K) Hematoxylin and eosin (H&E) staining depicted steatosis as circular white gaps caused when the dehydration process leaches the fat out of fixed liver tissues.

(L) The degree of steatosis was scored and represented as means ± SEM.

(M) Periodic acid-Schiff (PAS) staining for the detection of polysaccharides (e.g., glycogen) in fixed liver tissues.

(N) Semi-quantification of PAS staining and representation as means ± SEM.

(O) Dot blot depicting protein carbonylation levels in the liver of the six experimental groups of mice (n = 4/group).

(P) Quantitative analysis after normalization to protein content.