Is there a minimum calorie intake that is recommended for bfast?

i eat baguette with cheese & next fruits mixed with honey and then ride my bike to the coffeshop where i read a couple of pages from an inspirational book while iam drinking my nescafe .

I think you should eat what feels right for yourself. Although the best is probably a bit less than a third of your daily intake, if it feels like too much you can probably take it easy until it feels more natural.

It varies a lot, depending on your body type. Personally, I've struggled with weight gain – so I eat a bowl of granola for breakfast, then eat a large lunch and dinner with many snacks. If you are trying to lose weight, you could eat a low-fat parfait (yoghurt, granola, fruit). It tastes good, and has a lot of nutrients.

I'm sure there's a science to it but personally the only, even slightly successful, diet I've ever been able to stick to consistently is intermittent fasting. So I eat zero calories for breakfast every day. In fact I really only eat one meal a day after 6pm. I've been doing that for a couple months at a time and I'm still alive