Your child may not fit into their usual chair for feeding so you may need to find alternative ways to keep them upright while they eat. You can keep them upright on a bean bag or a buggy, depending on their size.
Small babies may sit on your lap to feed and if you are breast feeding, extra pillows may make this more comfortable for you both. Cover the cast with a towel, bib or long sleeved apron during feeding times to avoid accidental soiling.
For older children who cannot sit up in the cast try placing a pillow behind them to bring them up a little for feeding and ensure they eat small mouthfuls slowly whilst you are present.
Being in a spica cast does not restrict your child from eating the foods they normally would. However, be mindful they do not eat too much as they may become bloated and uncomfortable. Eating smaller meals more often may help to avoid this.