Feeding to much or too little?

Hi all milo is 5 month old, he is fed wagg puppy kibble and pedigree wet food pouches,
Not sure if he's getting too little or too much below is is feeding routine

Breakfast 7am. 43g kibble (wagg)
Lunch 12.30pm. 50g wet food (pedigree)
Eve 5pm 43g kibble (wagg)

So roughly 135g food per day. With training treats extra

He used to be a grazer and could have kibble down for a good while but now as soon as it's down he's eating it within 5-min

He walks twice a day. Appx 2 to 2.5 mile a day
With a little run round on bathroom breaks on garden

He was last weighed by the vet on 24.02.17. At 3.4kg

Any help would be greatly appreciated thanks