When pain persists on a chronic level the adrenals secrete an excessive amount of cortisol and catecholamine This in turn makes glucose serum levels unstable. (Tennant & Herman 2002). When blood sugar levels are too low the effects can include fatigue, dizziness and anxiety. When blood sugar levels are too high this can lead to frequent headaches and difficulty concentrating.
Other effects of excessive sugar intake include a reduction in a chemical called Brain Derived Neurotrophic Factor (BDNF). This chemical is required for normal cognitive function like learning and memory. Fasting is a recognized trigger for migraines and it is advisable to eat regularly and healthily and minimize severe highs and lows of blood sugar levels.