How about the opposite? Think about a time that you were really, really hungry. Were you tired and sluggish? I doubt it. You were probably hyperalert, your senses sharp as a needle. Animals that are cognitively sharp and physically agile during times of food scarcity have a clear advantage when it comes to survival. If missing a single meal reduced our energy and mental acuity, we would have even more trouble finding food, making it more likely that we would go hungry again, leading to a vicious cycle ending in death.
