Honestly, if it makes you feel good and productive to equate hunger with fat loss, I'd say go for it!

We all need motivation where you can get it.
A rumbling tummy just means that your stomach is preparing to receive food by beginning to release digestive juices, based on a trigger from the brain saying "food is coming". Now the reason your brain may be saying that could be one of a dozen things - maybe it's noon and you always eat at noon, or maybe you smelled your deskmates lunch, or maybe you saw a commercial for a hamburger ... etc. That rumbly-tummy-empty-feeling is all brain triggered.
But factually, hunger is not any indication of potential fat loss.
Sorry.
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