Figure 1. A schematic representation of the experimental design showing the number of litters generated and mice used for each set of measurements.

Mice born to well‐nourished control dams were cross‐fostered at 1 day of age to dams fed either a control diet (CON) or an isocaloric low protein diet (LP) to induce postnatal undernutrition (PUN) until weaning. All mice were weaned at 21 day of age to the control diet, thus limiting the period of undernutrition from day 1 to 21 days of age. During adulthood (70–90 days of age) mice were subjected to several tests to assess cardiac function via a maximal ${\dot{V}}_{{\mathrm{O}}_2}$ test, echocardiography and Doppler measurements, and cardiomyocyte calcium transient analysis.