issyuukanburi ni syokuyoku ga modotte, kyou ha asagohan wo zenbu taberareta.

一週間ぶりに means for the first time in a week or after a week.

• 一週間 = one week
• ぶり = after an interval; for the first time in ...
• に marks it adverbially, so it modifies what follows

So 一週間ぶりに食欲が戻って means my appetite returned for the first time in a week.

A very common pattern is:

• Xぶりに ... = for the first time in X ...

Examples:

• 三年ぶりに日本へ行った。 = I went to Japan for the first time in three years.
• 久しぶりに会った。 = I met them for the first time in a while.

In Xぶりに, the に helps the phrase act like an adverb, modifying the action or event that follows.

So:

• 一週間ぶり by itself = a one-week gap / after one week
• 一週間ぶりに戻る = to return after a week / for the first time in a week

In this sentence, に connects 一週間ぶり to 食欲が戻って.

Because 戻る is an intransitive verb.

• 戻る = to return, to come back
• Intransitive verbs do not take a direct object with を
• The thing that returns is marked with が

So:

• 食欲が戻る = appetite returns

If you used 戻す, that would be the transitive version:

• 食欲を戻す = to restore appetite, to bring appetite back

But here the sentence is describing the appetite itself coming back, so 食欲が戻る is natural.

Because 食欲 is the thing that returned.

In 食欲が戻る:

• 食欲 = appetite
• が marks the subject of 戻る
• 戻る = return

So the structure is basically:

• Appetite returned

This is very natural in Japanese with intransitive verbs like 戻る, 増える, 減る, 始まる, etc.

戻って is the て-form of 戻る. Here it connects two related events:

1. 食欲が戻って = my appetite came back
2. 今日は朝ご飯を全部食べられた = today I could eat all my breakfast

So the て-form works like and, or sometimes and then.

The sentence does not necessarily mean a strict sequence like a list of separate actions. It can also show a natural connection:

• My appetite came back, and because of that, today I was able to eat all my breakfast.

は marks today as the topic or contrastive frame.

So 今日は means something like:

• as for today
• today, at least
• today

It sets the scene for the second part of the sentence.

There is also a slight contrastive feeling here. It can suggest something like:

• Today, unlike recent days, I was able to eat all my breakfast.

Using 今日が would sound unnatural here because today is not the subject of eat.

Because 朝ご飯 is the direct object of 食べられた.

• 朝ご飯 = breakfast
• を = object marker
• 食べられた = was able to eat

So:

• 朝ご飯を食べられた = was able to eat breakfast

That is standard verb-object structure.

全部 means all or completely, and here it modifies the eating action.

• 朝ご飯を全部食べられた = I was able to eat all of my breakfast

You can think of it as:

• I ate my breakfast completely
• more naturally in English: I ate all my breakfast

Its placement is normal. In Japanese, adverb-like words such as 全部, よく, たくさん, あまり often come before the verb.

食べられた is the potential form in the past tense, meaning was able to eat or could eat.

• 食べた = ate
• 食べられた = could eat / was able to eat

This matters because the sentence is not just saying breakfast was eaten. It is emphasizing that eating it was possible, probably because the speaker had been unable to do so recently.

So the nuance is:

• Today, I managed to eat all my breakfast.
• Today, I was finally able to eat all my breakfast.

That fits well with the earlier part about appetite returning.

In form, 食べられた can look like either:

• potential past: could eat
• passive past: was eaten

But in this sentence, it is clearly the potential meaning.

Why?

Because the object is 朝ご飯を. With the potential meaning in everyday Japanese, を is common:

• 朝ご飯を食べられた = I could eat breakfast

A passive reading would not make sense here:

• Breakfast was eaten would not fit the context of appetite returning

So learners should understand this as was able to eat.

Japanese often leaves out subjects when they are clear from context.

In this sentence, the person is understood from the overall meaning:

• my appetite came back
• I was able to eat all my breakfast

So 私は is unnecessary unless the speaker wants emphasis or contrast.

This is extremely common in Japanese. A natural English translation often needs I or my, even when Japanese does not state them.

No. 朝ご飯 is natural and common, but there are other possibilities.

Common ways to say breakfast:

• 朝ご飯
• 朝ごはん
• 朝食

Nuance:

• 朝ご飯 / 朝ごはん feels everyday and conversational
• 朝食 sounds a bit more formal or written

So this sentence could also be written with 朝ごはん and still sound very natural.

The sentence gives a sense of relief and recovery.

The flow is:

1. After a whole week, my appetite finally came back
2. As a result, today I could eat all my breakfast

So it sounds like the speaker had been sick, stressed, or unable to eat properly, and this is a positive change.

That is why the potential form 食べられた is especially effective: it highlights that eating normally had not been possible before.