8 – Optimize fetching data from entity objects

Currently we are using EntityTypeManager to either load or loadMultiple :

$this->entityTypeManager->getStorage('node')->loadMultiple($nids);
$this->entityTypeManager->getStorage('node')->load($nid);

This creates and returns objects of nodes which I think uses much resource on the server (since it fetches all fields). We’re also trying to fetch around 500 nodes, and each has over 80 fields.
We only want to fetch certain fields.

Does anyone know a way to query and fetch only the certain fields needed?