"I am not hungry at all."
Well you can figure that out by knowing the literal meaning of the phrase: おなかがすきました means 'My stomach became empty' (so that's why I am hungry right now), so when you say ぜんぜんおなかがすきません you express the current state of your stomach: 'My stomach is not empty at all' -> I'm not hungry right now. おなかがぜんぜんすきませんでした probably refers to not being hungry sometime in the past.
Not really. 全然 stresses the fact of not being hungry so the example is correct, if you mean that you are not eating anytime soon - but I guess the listener is going to think you have a compelling reason for avoiding the meal.
I never heard お腹がすきません because it sound strange in Japanese. It says that you won't be hungry as if you are refusing to eat, otherwise you would have said to be full with the standard お腹がいっぱいです。
お腹がすきました。Or more commonly お腹がすいた。 is the correct way to say you are hungry, as it has been pointed out.
I'm making this comment after doing some research, it seems like there are already some comments here about this particular sentence being wrong but not enough to make a contributor change it.
空く "to get empty"
お腹が空く "stomach gets empty"
お腹が空いた "stomach got empty" (past) implies "I'm hungry"
お腹が空いている "stomach is in the state of empty" or "I'm hungry"
お腹が空いていない "stomach is not in the state of empty" or "I'm not hungry"
お腹が空かない "stomach doesn't get empty"
お腹が空きません "stomach doesn't get empty" (polite)
as Kazu136745 pointed out in another comment, the Japanese sentence "I am not hungry at all" should be「全然お腹が空いていません」
「全然お腹が空きません」can be translated as "My stomach doesn't get empty at all" or "I don't get hungry at all".
Here is a quick example from the web, a Japanese middle school girl explaining this as a symptom and having trouble with her mom because of that:
Here is another one where a man asks「この時間お腹が空きませんか？」"doesn't your stomach get empty at this time?" or "don't you get hungry around this date?" speaking about eating soba while in new years eve:
There are also several E-J dictionaries online with sentences similar to this with the very same mistake, which was the reason why I didn't want to say it was wrong (I assumed it was some sort of phrase in Japanese), I'm gonna guess the mistake doesn't directly come from duo but from mining that kind of data. And it just hasn't caught the eye of a contributor yet.
These look fine. ぜんぜん（全然 ）can go in either place. As japan_ichiban explained, お腹がすきません is "I am not hungry," and お腹がすきました is "I am hungry." Or with all kanji, some arrangement of 全然お腹が空きません. It is useful to notice that the すき here (空き), is not the すき(好き) we learned earlier in the course.
Not really, i commented common -expressions- of hunger above, you're just throwing around words to see what sticks.
お腹が全然空きせん would be "I will not [feel] hunger in my belly at all" 全然お腹がすきません would be "I do not hungry belly at all"
Expressions are just that. They're expressions, they're not really something you can use as a grammatical playground.