Our bread contains a lot of whole grain flour. Don't underestimate how that effects how full you feel.
When losing weight I found I could easily get away with skipping lunch entirely, just two or three slices of bread as a late breakfast. But only if the bread had sufficiently high amount of whole grain flour (>90%). The days I only got hold of 50-60% whole grain bread I had to top up with a small lunch.
It's probably the fiber content, if I had to guess. Fiber is really good at making you feel full, which is why psyllium husk is sold as a dietary supplement.
When losing weight I found I could easily get away with skipping lunch entirely, just two or three slices of bread as a late breakfast. But only if the bread had sufficiently high amount of whole grain flour (>90%). The days I only got hold of 50-60% whole grain bread I had to top up with a small lunch.