@woollygal - I look at it in a way others haven't expressed here, in that I consider if I'm not eating carbs, I don't have access to a quick hit of sugar for energy, so I need to fuel differently. The proteins and fats we eat take longer to become energy, but they do become energy in their own time. By energy I mean fuel, as opposed to Tigger style bouncy, bouncy get up and go.
In essence, in your shoes, I would try to increase my breakfast a bit. If not add by adding another rasher of bacon, an egg or whatever, then maybe by having some yoghurt too. If you have that early enough, it will turn to fuel in due course. The timing is very personal, as our digestions all work at different paces.
Might be worth thinking about.