Shaykh, I'm 18 and weigh about 104 lbs. My BMI says I'm underweight. If I gain weight to reach a healthy weight, would that be disliked in Islam despite the hadith about eating less? Also, how many meals should we eat daily, how much should we eat, and how did the Salaf generally eat and drink?
Ustadh AbdulAziz al-Haqqan
No — reaching a healthy weight is not disliked. What the texts censure is excess and gluttony, not nourishing the body; and the scholars state that eating with the intention of gaining strength for the obedience of Allah is itself rewarded. Islam sets no fixed number of daily meals. Allah Jalla wa ʿAlā (the Majestic and Exalted) says, the meaning of which is: "and eat and drink, but be not excessive" [al-Aʿrāf, ayah 31]. And the Prophet ﷺ said: «بِحَسْبِ ابْنِ آدَمَ أُكَيْلَاتٌ يُقِمْنَ صُلْبَهُ...» Meaning: "A few morsels suffice the son of Ādam to keep his back straight — and if he must have more, then a third for his food, a third for his drink, and a third for his breath." (reported by al-Tirmidhī; its chain graded ṣaḥīḥ by al-Albānī raḥimahullāh)