Did i give myself brain damage

would not eating for 20-36 hours (during this time getting dizzy/fuzzy), staying well hydrated & (maybe drinking 1 or 2 sugary soft drinks during-usually mountain dew) once a week or possibly twice (at least a day of healthy eating between purges) for a few months cause brain damage? in other words, do you think any brain cells would starve or resort to autophagy (lets say the person is 20-25 pounds overweight)? that was when i was 16, i practiced this poor nutrition for 3 months, and resumed to one day a week or less 2 months after (i now eat healthy and work out).