Intermittent fasting and sleep

A late or unusually large meal can cause reflux, fullness, or abdominal discomfort at bedtime, while an early last meal may leave some people hungry overnight. Drinking too little during the eating window can cause thirst and dehydration. Caffeine used to manage hunger may delay sleep. Changes in eating can also alter bowel patterns; constipation can be worsened by low fluid or fibre intake. Ongoing sleep disruption may have another cause, including irritable bowel syndrome, thyroid disease, or diverticular disease, so fasting is not the only explanation.

Keep the fasting and eating windows consistent for several days rather than changing them nightly. Place the last substantial meal far enough before bedtime to allow digestion, and choose balanced foods with fibre and protein. Drink regularly during the eating period unless a clinician has restricted fluids. Limit caffeine later in the day and keep a note of hunger, bowel movements, bedtime, and awakenings. If constipation or sleep problems continue, a nutrition counselling appointment can help adapt the plan to your needs.

Seek urgent help for severe abdominal pain, repeated vomiting, fainting, confusion, or signs of significant dehydration such as inability to keep fluids down. Arrange a medical review for persistent constipation, blood in the stool, unexplained weight loss, or sleep disruption that affects daytime function. Ask for advice before fasting if you have a diagnosed bowel or thyroid condition.

Is my chosen fasting window suitable for my bowel and sleep symptoms? How much fluid and fibre fit my health needs? Could medicines, thyroid function, or another condition be affecting my sleep or constipation?