Biological growth is coordinated over many time and length scales - right from the inner workings of the cell at the molecular level all the way to population level responses in the face of environmental changes. In this context, I will discuss biophysical mechanisms of size and growth control at the organelle, organism and population level. Using the multicellular nematode C. elegans I will address how an organism organises its cellular contents and regulates the size of its internal structures with functional consequences on growth. Interestingly, organism size itself governs developmental progression under changing food availability. Finally, I will present data showing worm populations modulate their investment in growth and reproduction when their food source is dynamically redistributed. Altogether, these table-top experiments provide an exciting opportunity to explore adaptive life history strategies with broad and important consequences in both developmental biology and ecology.