224g fat triggers massive CCK (cholecystokinin) release — the hormone that tells your brain "stop eating." You'd feel uncomfortably full within 20 minutes of starting and likely wouldn't finish the jar. Your body has built-in limits for fat intake.
That's more than most people's total daily energy expenditure. If done once: stored as glycogen (limited capacity ~2000 cal) and fat (unlimited). You'd gain ~0.3 lbs of actual fat from one jar. The scale would show 2-3 lbs more tomorrow from water retention (sodium + glycogen binding water). That's temporary.
224g fat in one sitting overwhelms bile acid production. Undigested fat reaches the colon → osmotic diarrhea + steatorrhea (fatty stools). You'd spend quality time in the bathroom within 2-6 hours. The high fat + moderate fiber (6g/100g) combination is powerful.
📋 Verdict
One jar once won't harm you beyond GI distress. The bigger danger is finishing "just a little more" repeatedly — peanut butter is extremely calorie-dense and easy to overeat. If you find yourself regularly eating half a jar in one sitting, consider: are you undereating protein at meals? Peanut butter cravings often signal inadequate protein or fat earlier in the day.