The primary metabolic pathway required to produce ATP differs as a result of tissue type, developmental stage and substrate availability. We utilised molecular and histological techniques to define the metabolic status in fetal and adult, adipose and skeletal muscle tissues. Redox ratios of these tissues were also determined optically by two-photon microscopy. Adult perirenal adipose tissue had a higher optical redox ratio than fetal perirenal adipose tissue, which aligned with glycolysis being used for ATP production; whereas adult skeletal muscle had a lower optical redox ratio than fetal skeletal muscle, which aligned with OXPHOS activity being utilised for ATP production. We have compared traditional molecular and microscopy techniques of metabolic tissue characterisation with optical redox ratios to provide a more comprehensive report on the dynamics of tissue metabolism. This article is protected by copyright. All rights reserved.