Is it understood from the Noble Verse and the Honorable Hadith that eating once a day is better, and that exceeding this is considered blameworthy extravagance, and does this apply to fasting days, and what is the ruling on limiting oneself to milk with honey, a piece of meat, and fruits at specific times of the day?

Extravagance (israf) is blameworthy in eating and other matters. The difference between it and squandering (tabdhir) is that extravagance is spending something on what is permissible but in excess of what is necessary, whereas squandering is spending it on what is not permissible. Extravagance is exceeding the limit, like eating beyond satiety, and it is not defined by a specific number of meals.

The purpose of eating is to preserve the body and gain strength for acts of obedience in moderation, neither with gluttony nor with debilitating hunger.

Eating has levels: Obligatory (fard): What prevents perishing. Rewarded (ma'jur 'alayh): What is in excess to facilitate worship easily. Permissible (mubah): What reaches the point of satiety to increase bodily strength (neither reward nor sin). Forbidden/Disliked (haram/makruh): Eating beyond satiety in a way that harms the body, or that causes heaviness and hinders worship.

There is no harm in eating more than one meal a day, as long as it does not involve extravagance (eating beyond satiety). The Companions indeed ate until they were full in the presence of the Prophet, peace and blessings be upon him.