Sleep is one of the less obvious things people notice changing when they go keto, and the reports cut both ways: some find they sleep more deeply within weeks, others have a rough patch of broken sleep at the start. Both are real, and a 2024 review helps make sense of why.
What the research found
A scoping review published in the Journal of Sleep Research in 2024 gathered the studies on ketogenic dietary therapies and sleep. The overall picture was encouraging. Across the research it found improvements in several aspects of sleep: better overall sleep quality, less difficulty falling asleep, fewer awakenings during the night, reduced daytime sleepiness, and in some studies an increase in REM sleep. Other work points to more slow-wave sleep, the deep, physically restorative stage, on a ketogenic diet. So the weight of evidence leans towards keto improving sleep once a person is established on it.
Why it might help
A couple of mechanisms are proposed. Ketones provide the brain with a steady fuel, which may help stabilise the overnight metabolism that can otherwise disturb sleep. There is also interesting work on adenosine, a brain chemical that builds up through the day, makes you progressively sleepier, and promotes deep slow-wave sleep at night; ketogenic diets appear to influence this system. And more prosaically, cutting out sugar and refined carbohydrate tends to flatten the blood-sugar swings that can cause restless nights and early waking. None of these is fully settled, but together they make the sleep improvements plausible rather than coincidental.
The rocky start
Here is the part that catches people out. The first week or two of keto can actually worsen sleep before it improves it. As the body shifts fuel sources it sheds water and salt, and the resulting electrolyte changes, along with a temporary rise in stress hormones, can cause wakefulness, lighter sleep and that wired-but-tired feeling. This is part of the same adjustment phase as the so-called keto flu. Crucially, it usually passes. Keeping your electrolytes topped up, particularly sodium and magnesium, smooths the transition and often resolves the early sleep disruption, after which many people sleep better than before.
What it means in practice
The sensible approach is patience. Do not judge keto’s effect on your sleep in the first fortnight, because that is exactly when it is most likely to be temporarily worse. Give it several weeks past the adjustment period, keep your salt and minerals up, and avoid the usual sleep saboteurs like late caffeine and screens so you are not blaming the diet for something else. If your sleep settles and deepens, as the research suggests it often does, that is a genuine bonus on top of the other reasons for eating this way.
Keeping it honest
The evidence is promising but not uniform. Some studies found no change, the effect varies between individuals and populations, and the clearest benefits have been seen in specific groups such as people using ketogenic therapy for epilepsy. Sleep is also influenced by far more than diet, so keto is one lever among many. The fair summary is that keto tends to help sleep for many people once they are adapted, with a likely rough patch at the start, rather than a guaranteed cure for poor sleep.
The bottom line
A 2024 scoping review found that ketogenic diets are generally associated with better sleep quality, easier sleep onset, fewer awakenings and more deep sleep, probably through steadier brain fuel, effects on the adenosine system and flatter blood sugar. The catch is a possible rough first couple of weeks during adaptation, which good electrolyte intake helps. Be patient through the start, and better sleep is a realistic reward.
This is general information about the ketogenic diet, not medical advice. Persistent sleep problems can have medical causes worth investigating. If you are pregnant, on medication, or managing a health condition, speak to a professional before changing your diet.
Source: Pasca L, et al. The effects of ketogenic dietary therapies on sleep: A scoping review. Journal of Sleep Research. 2024. Read it here.