The article from Healthline-website linked in the question provides for the Health benefit aspects of fasts. Fasts are one type of vratas, and the major purpose of the fast is spiritual progress, not bodily progress.
In any case, what Devarishi Narada says, seems mostly in reference to some specific diseases, and not the general health benefits like Autophagy?? and other concepts talked about in the scientific jargon.
Nevertheless, we do have some statements which are similar to the words of Devarishi Narada, in reference to fasting and diseases.
Rishi Agastya narrates a similar outcome of a fast to alleviate leprosy and get sound health. Infact the name of the vrata is itself Arogya-vrata (literally, the Vow for Health)
62 , Arogyavrata, Varaha Mahapurana
अनेन वत्सरं पूर्णं विधिना योऽर्चयेद् रविम् । तस्यारोग्यं धनं धान्यमिह
जन्ममि जायते । परत्र च शुभं स्थानं यद् गत्वा न निवर्तते ।। ६२.५ ।।
- One who performs this worship of the Sun duly for one full year, gets health, wealth and grain in this life, and gets in the other
world a place from where he need not return.
सार्वभौमः पुरा राजा अनरण्यो महाबलः । तेनायमर्चितो देवो व्रतेनानेन
पार्थिव । तस्य तुष्टो वरं देवः प्रादादारोग्यमुत्तमम् ।। ६२.६ ।।
- In days of yore, the glorious and valiant king by name
Anaranya propitiated the god by this Vrata, as a result of which the god was pleased and he bestowed upon him sound health.
सोऽपि राजाऽकरोच्चेमं व्रतं भक्तिसमन्वितः । सिद्धिं च परमां प्राप्तो
विरोगश्चाभवत् क्षणात् ।। ६२.३४ ।।
- Therefore, O king, you also perform this vrata and by its power you will be cured of leprosy.
English Translation by Motilal Banarsidass Publishers