Research Paper Volume 12, Issue 9 pp 7963—7984

Metabolic switching is impaired by aging and facilitated by ketosis independent of glycogen

Figure 5. Metabolic biomarker levels while keto-adapting. (A) Young rats fed a KD demonstrated immediate decreases in insulin levels. Aged rats did not demonstrate similar declines until after the first week of adaptation. (B) Neither young nor aged rats fed the SD, even in conjunction with TRF, demonstrated changes in insulin levels until the end of the 4th week, at which point aged rats demonstrated decreased insulin levels. While aged rats on both (C) the KD and (D) the SD had significantly higher leptin levels than young rats on the same diet, only aged KD-fed rats demonstrated significant decrease over time. (E) C-Peptide levels were significantly lower in young rats relative to aged when fed a KD (F) but not an SD, though neither group demonstrated significant differences over time. (G) HOMA values were significantly higher in aged KD-fed rats relative to young at the start of the diet, but this difference was ameliorated by day 28. (H) However, aged rats fed an SD did not see improvements in HOMA over time. Data are represented as group mean ± 1 SEM. * = p < 0.05. For all panels: n = 5 per group for all groups.