B.G 4.30
apare niyatāhārāḥ prāṇān prāṇeṣu juhvati। sarve'pyete yajñavido yajñakṣapitakalmaṣāḥ ॥30॥
Still others regulating food offer the life force into life force. All these are indeed knowers of Yajna, and have their impurities cleansed by Yajna.
Gīta Bhāshya 4.30
"Offering life force onto life force" - means limiting the consumption of food.
niyatāhāratvenaiva prāṇaśoṣāt prāṇān prāṇeṣu juhvati।
By regulating the diet alone, the weakening of the life force occurs, and life force is offered into life force.
"yacchedvāṅmanasī prājñaḥ" (kaṭhopaniṣad 1.3. 13)
"Control speech with mind, and mind with wisdom..." (kaṭhopaniṣad 1.3. 13)
ityādi śrutyukta prakāreṇa vā। anyadapi granthāntare siddham
Such Vedic testimonials confirm its accuracy. Other testimonials also confirmed it, such as:
"yadasyālpāśanaṁ tena prāṇāḥ prāṇeṣu vai hutāḥ"
iti ॥30॥
"Indeed, by consuming a small quantity of food, life force is offered into the life force."
- thus.