• Quantitative energy metabolism and substrate partitioning unify the era’s metabolism work, tying basal metabolic references to fat vs carbohydrate energy tradeoffs across animals and humans and integrating whole‑body energetics with organ-level data [3], [10], [13], [14].

• Cellular energy production and organ metabolism are linked through mitochondria and in vitro cell metabolism studies, connecting mitochondrial function to heart–lung carbohydrate metabolism and systemic gas transport [2], [3], [10], [18].

• Endocrine and reproductive regulation of metabolism emerges as a core theme, detailing how endocrine glands modulate metabolism, and how lactation and mineral exchange reallocate metabolic pathways [7], [16], [17].

• Model systems spanning actinomycete metabolism, pig endogenous metabolism, and microbial carbohydrate metabolism reveal conserved biochemical pathways and metabolic states across kingdoms: microbial, animal, and cell systems [5], [9], [12], [18].

• Bile- and liver-linked metabolism shows hepatic processing of bile pigments and bile acids as central metabolic routes, highlighting liver physiology and secondary metabolism [8], [11].