Eat normally before an ambulatory EEG. There is no fasting requirement and skipping meals is actively unhelpful, because low blood sugar changes the recording. The one restriction is usually caffeine, and you should follow whatever instruction you were given.
Eat normally before an ambulatory EEG. There is no fasting requirement and skipping meals is actively unhelpful, because low blood sugar changes the recording. The one restriction is usually caffeine, and you should follow whatever instruction you were given.
Unlike studies involving sedation or contrast, an ambulatory EEG has no reason to require an empty stomach. More than that, arriving hungry works against the study: low blood glucose alters the electrical background and can introduce changes that complicate interpretation. Eat a normal meal before the fitting appointment, and continue eating normally throughout the recording days, since the whole point is to capture ordinary life rather than an artificially altered version of it.
Caffeine restriction is the most common instruction, because caffeine influences the electrical background and can suppress the drowsy states in which useful activity often appears. Whether it applies, and for how long, depends on the question the study is answering, so follow the specific instruction you were given rather than a general rule. Alcohol is usually discouraged during the recording, both because it alters the trace and because it disturbs sleep, and sleep is frequently when the most informative activity shows up.
Some studies are deliberately arranged after a short night, because drowsiness increases the chance of capturing abnormal activity. If you have been asked to restrict sleep, that instruction is doing real diagnostic work and should be followed precisely. It also changes your travel arrangements: arrange a lift rather than driving yourself when sleep-deprived. Take your regular medications as normal unless specifically told to hold one, and never stop an anti-seizure medication on your own initiative.
Clinical Neurology Specialists has been physician-owned since 1998, when Leo Germin, M.D., FAANEM founded it. Five board-certified neurologists and four advanced practice providers see patients at the Las Vegas and Henderson offices, each with its own AANEM-accredited electrodiagnostic laboratory.
Clinical Neurology Specialists is an adult outpatient neurology practice for patients 18 and older. The practice performs no surgery and operates no imaging suite, infusion suite or interventional pain programme, and provides no emergency or inpatient care.
Physician-reviewed. Reviewed by the physicians of Clinical Neurology Specialists — board-certified neurologists, AANEM-accredited electrodiagnostic laboratories, physician-owned since 1998. Reviewed 1 August 2026. This article is general education for adults 18 and older and is not a substitute for a consultation.
Sources and further reading: MedlinePlus: electroencephalogram (EEG); MedlinePlus, National Library of Medicine; MedlinePlus: epilepsy.
Adults 18 and older, at the Las Vegas and Henderson offices. Call 702-804-1212 or request an appointment online.