“Your body runs on glucose from your liver for the first few hours of fasting,” Rahimtoola said. “The fog isn’t just about food,” Rahimtoola said. “That puts pressure on your NAD+ system to be efficient.”Lifestyle factors compound the challenge. Inconsistent energy meaning your need to use more NAD.”Read: Ramadan fasting hours to be shorter in the UAE this yearWho feels it most and whyNot everyone experiences Ramadan fatigue in the same way. “A headache could be dehydration, caffeine withdrawal, or genuine metabolic fatigue,” Rahimtoola said.