It's not easy. To diet, I did well when I ate a bowl of muesli for breakfast (plain, not high-fat, high-sugar, toasted). But I now have a problem with oats which puts just about all decent breakfast cereals off my list.
I've done better on our Aussie CSIRO diet, which is a low-GI, moderately low carb diet. But it uses a lot of beans and through following that diet and cooking my own beans, I now find I can't eat anything in the kidney bean family.
So I'm concentrating mostly on low GI, although I'm less fussy in the morning. Yoghurt for breakfast, a glass of milk when I feel hungry, lots of water, maximum one slice of bread a day, eggs. My favourite decadent breakfast is omelette, with prawns and fresh herbs; or maybe omelette with fresh cooked asparagus and a generous blob of bearnaise sauce (home-made, of course). I have a great microwave recipe for bearnaise, then I keep the sauce in the fridge or freezer and we all enjoy it.
If I'm in a hurry, I do two or three fried eggs (bantam eggs, they're tiny). I break them into a non-stick pan then turn off the hot plate. There's enough residual heat to cook them through while I go get dressed. They never burn, they're always done just how I like them and I don't have to stand and watch them. No toast. Maybe a bit of bacon (cooked first, to get the fat so I can cook the eggs in it).
Another diet version (also related to CSIRO diet) is to make sure you eat from at least fifteen different plant sources each day. It's a challenge and it really keeps your variety in your diet, as well as the amount of vegetables and fruit you eat. Yes, herbs count too. So an omelette with garlic chives, onion chives, parsley and basil already has four different plant origins in it. Serve with fresh fruit and there's more. Bearnaise - another one, for the tarragon that goes in it.
Enjoy!
Marg