Varies quite a bit. Looking at the past week:
Homemade sourdough toast, sausages, grapes
bagels with cream cheese and lox
hash browns with fried egg and homemade Hollandaise sauce
Carribean-style coconut-rice porridge with mangoes and limes

This week I started eating a butter sandwich as soon as I wake up in the morning. And when I say “butter sandwich” I’m talking about eight pats of butter between two slices of whole wheat bread.

About 450-500 Calories, 30% Carbohydrates, 6% Protein, 64% Fat (two-thirds of that is saturated fat) – that’s with regular bread, whole wheat improves this somewhat.

Why is this so satisfying? I’m not hungry until late in the afternoon, at which point I just wait until dinnertime.

It’s because the fat content. It’s got enough carbs (fast arc energy) to take care of an immediate hunger. It’s got a lot more fat (slow arc energy) that gives you long-lasting satiety.

I’d like to lose some weight, and with these butter sandwiches I’m consuming much less food during my day, but they can’t be healthy for me. Clearly I don’t know how nutrition works.

I’ve learned this as I went along. I went from 298 lbs to 171 and I’ve kept it off for 8 years so far. Think of it as a series of trade ups that you make along the way when you learn thing and you are ready to do them. Doing too much too fast is how to get frustrated and quit.

To lose weight, we have to take in less energy than we burn and the proverbial average person burns about 2000 Calories a day. To get enough food for basic nutrition (essential fatty acids, enzymes, minerals, vitamins) we need to eat enough and eat through a wide variety of healthy food through the week. Most of us can cut back 25%-33% of what we were eating before and shed some pounds, so the rest has to be good with nutrition.

Missing in your breakfast and lack of lunch are sources of sufficient protein (such as some meat for example) and vegetables which provide a lot of our vitamins and minerals. But like you said, this is good for weight loss. Now make it smarter in some way, in YOUR way. Don’t try to aim for the optimal way, but what’s a veggie (or fruit) you might add or have on the side with it? When you choose it, it’s easier to make happen. And some fruits are pretty portable and you can have it later that day and prevent that afternoon hunger.

On the constructive criticism side, butter is a saturated fat and the Heart Association recommends aiming for a dietary pattern that achieves 5% to 6% of calories from saturated fat to avoid health problems. The 8 pats of butter are just under 300 Calories and 120 or so would be the Heart Association’s recommended amount. But, here too, trade up and do baby steps. It’s a journey and it has to stay your diet and not be too weird to you. You can choose a butter-like spread that is mostly unsaturated and satisfy both your taste buds and your heart needs.

What do you eat in the morning?

A bowl of 0.5c Cheerios, a few nuts, some milk, and a fruit – all mixed together. It’s small, only about 250 Calories, but I eat again mid-morning when the spouse wakes up. Our main big meal is before noon. We have a light supper later, sometimes what other Americans would think of as a lunch, such as soup and salad.

Or if you are familiar with the McDonald’s Sausage McMuffin with Egg, I make my own with turkey sausage. If I don’t have that cereal/fruit/nut thing above, I make this.