Ghrelin — The Stomach’s “I’m Hungry” Signal
The hormone that rises before meals, nudges you toward the fridge, and spikes when you try to diet hard.
Ghrelin is a hormone produced mainly by the stomach. Its levels rise during fasting and just before expected mealtimes, then fall after you eat. It travels through the blood to the hypothalamus and other brain regions, switching on hunger neurons and making food cues more appealing.
Think of ghrelin as your body’s “go find food” text message. It doesn’t care about macros or morality; it simply reports that the gut is empty and energy intake hasn’t happened in a while. When ghrelin is high, it not only increases appetite but can also make high‑reward foods (think sugar‑fat combos) especially compelling via the mesolimbic-reward system.
When you deliberately cut calories, ghrelin goes up as part of the defense system around weight. The longer and more aggressively you diet, the more your body interprets this as potential famine, and the louder ghrelin gets — which is why white‑knuckling through extreme restriction often ends in over‑correction.
GLP‑1 therapies and structured eating patterns don’t erase ghrelin, but they can moderate its peaks and help your brain interpret “I could eat” versus “I’m starving” more accurately. Stable meals, enough protein, and sleep also tame ghrelin; erratic snacking, chaotic schedules and chronic sleep debt exaggerate it.
Why It Matters
Knowing about ghrelin normalises why you feel hungrier when you diet or skip sleep — and makes it easier to design weight‑loss plans that work with biology instead of triggering its emergency alarms.
Closing Line
Ghrelin isn’t you being “weak”; it’s your stomach phoning the brain with a simple request — your job is to decide when that call genuinely needs answering.