A pound of peanut butter is around 2600 calories. A pound of Nutella is about 2400 calories. Honestly not as bad as I thought initially.
1 to 2 pounds a week is 370 to 740 calories per day. Eating that much peanut butter for a week or so wouldn’t be too hard, but keeping that rate up consistently would be tough.
Your second sentence made me think of this.