Is 3 hours high intensity exercise a week enough

Msdwyer17

Not really looking for weight loss, looking to lose body fat and gain a small amount of muscle mass for a more toned appearance.
I keep to a semi clean diet off eggs & a piece of toast for breakfast, Greek yoghurt a tsp chia seeds & 10 almonds snack, a chicken spinach salad at lunch, 1 tsp peanut butter cinnamon rice cake with carrot batons. Dinner is usually chicken again, with brown rice/wholewheat pasta, veg in a low sugar tomato sauce.
I eat fruit/extra carbs on workout days.

I workout 3 hours a week.

I always start off with 20 minute circuits (1 min warm up, 6 exercises done for 30 seconds 6 times, then 1 minute cool down) I do these 4 times a week, 3 times I add a 20 minute treadmill hiit.

I train using weights for 3 of the 20 min circuits, then just body weight circuits the other time.

As it only amounts to 3 hours I feel like I'm not doing enough. Should I be doing more? Please help