Fig 3. Time plots of continuous EE data calculated using the Weir RQ^- method and its correspondence to the standard Weir RQ⁺ method and RQ in a single mouse.

The thick solid lines indicate the dark photoperiod. (A) EE as computed by the RQ^- equation (see text or Fig 1). Median, 97.5th and 25th percentiles are indicated. (B) The RQ^- minus RQ⁺ EE difference. Mean ± 2 SD limits are indicated. (C) RQ. Median, 97.5th and 25th percentiles are indicated. Note that the Δ EE trace indicates remarkably little error between the RQ^- and RQ⁺ equations, but that it tends to rise to its most extreme values as RQ decreases. This fits with the predicted behavior of the RQ^- equation. EE, energy expenditure; RQ, Respiratory Quotient; Δ = Weir (RQ^-) minus standard the Weir (RQ⁺) EE difference.