No, this phrasing doesn't make sense.
Heavy food
When native speakers describe a food as heavy, they usually mean that it is rich in fats. Most commonly, foods described as heavy are meat dishes, although dishes full of dairy fat are also sometimes referred to in this way. Here are some examples:
- meatloaf and mashed potatoes
- mac and cheese
- a large hamburger
- pork chops
- pasta alfredo
Typically, vegetable dishes would not be referred to as heavy, unless they were also rich in fats from some other source like cream or meat. For example, The South (the region of the US), has a dish usually just called Greens which are leafy green vegetables such as mustard greens or collard greens that are stewed with seasonings and sometimes with bacon or pork fat. Greens could be a heavy dish if it tasted and felt very fatty, but not otherwise.
It doesn't make sense to refer to plain spinach as heavy. If the spinach was cooked in fat or served with something fatty, then it would be referred to by the name of the preparation style or dish (e.g., Creamed Spinach is a somewhat heavy dish).
Instead of heavy, you maybe meant one of these:
Restorative Dish
it is generally a restorative dish
This does not sound idiomatic. Usually when English speakers talk about feeling restored, they are referring to energy level, not nutrition or overall health. Here are some examples of things that might be described as restorative:
- A hot cup of tea - both for the caffeine and for the peace of mind that occurs when slowly sipping something warm
- A nap or a good night's sleep
- A soothing bath or trip to a spa
- A vacation spent relaxing by the beach
Mostly, food does not get described as restorative, so it's not clear what you mean here. Perhaps one of the following words would work?
- nutritious
- nutrient-dense
- healthy
Healthy but not for weak people
those who are in restoration
I think there may be a cultural barrier here. I'm not at all sure what you mean by this, and suspect that your culture has a concept that American culture doesn't have. If someone is sick, they generally are supposed to drink lots of liquids and eat simple foods that will be easy on their stomach (rice, plain chicken or fish, simple vegetables, etc.). But that person wouldn't be described as weak or as "in restoration."
The closest I can understand would be that athletes often have special dietary needs to support their bodies. In some cases, they need to eat much more than people need if they aren't exercising for several hours each day. So for example, someone who exercises a lot might eat multiple steaks, which would be healthy for them. But someone who does not exercise a lot should not eat that much. Or in other cases, they may need to maintain a certain body shape or size, and so not be able to eat things such as bread or added sugars. But most of the time in English-speaking countries, someone who is strong would eat the same things as someone who is weak.
How to say this
If you wanted to decline breakfast, here is a more idiomatic way to say that:
Do you want breakfast?
No, I ate a lot at dinner last night and it was very filling. I had spinach, which is quite nutritious.