Roti in breakfast?

I am a rather unconventional eater - I'd eat chapati in breakfast, and may eat an omelette in dinner. However, it's worth spending a few minutes on who defines what we should eat at different times of the day?

Our body has different calorie requirements at different times of the day, and hence, our breakfast, lunch, and dinner should be tailored to meet those requirements. Now, obviously, we have a range of food items that can meet those requirements. But how did we learn that we should eat flakes, bread, omelette in breakfast, and curry, rice, chapatti, lentils in lunch/dinner? Put in more contrast, how did we learn not to eat rice and lentils in breakfast, or not to eat an omelette in dinner? :-)

I am tempted to pass on the blame to the marketing of the products. When a new food item is launched, it's tied to an eating habit. Consider adverts of flakes telling us how good they are for breakfast. Most of us do not think critically and challenge the biases that these adverts introduce us to. Perhaps, it's the marketers way to enable purchases. :-)