Feeling thirsty and feeling hungry come from the same place in your brain — the hypothalamus — and it constantly mixes them up. The wiring overlaps so much that mild dehydration often shows up as a craving for a snack. You think your body wants food. It wanted water, and you misread the telegram.
The mix-up. A huge share of the "hunger" people feel between meals — the vague, restless, need-to-nibble feeling — is actually low-grade thirst wearing hunger's clothes. You eat, because the signal felt like hunger. The real need goes unmet, so an hour later the craving is back, and you eat again.
The test. Next time a random craving hits — not real mealtime hunger, the fuzzy kind — drink a glass of water first and wait ten minutes. A startling amount of the time, the "hunger" just dissolves. Because it was never hunger.
The bigger truth. The urge you feel and the thing you actually need are often two different things. You feel like scrolling — you needed rest. You feel like snapping at someone — you needed sleep. You reach for the obvious fix because the signal is loud, not because it's telling the truth.