Like rubybella I feed Millie's wolf heart working dog food . It's grain free and not full of rubbish and fillers . It was the only food that I found that kept weight on ernie , he's also a Wcs and is a very busy boy on the walk , he gets three walks a day off lead at different locations . The thing the tires him out most is a game of fetch and find it which I do on one of the walks each day and he absolutely loves it !
Although ernie is " busy " when he's out , he settles and sleeps in the house . But I know a lot of Wcs have different energy levels and my friend owns ernies " great aunt " and she's is like tiger on speed most of the time despite lots of exercise and games etc
Going back to the food , it maybe worth giving mark at millieswolfheart a ring , he's got a wealth of knowledge and is great at helping you find the right food ( they have different varieties of food with different protein levels etc ). Ernie has a 50/50 % endurance mix .
I hope that helps .