Am I Drinking Enough Water on Keto? The Urine-Colour Check
This is one of the shortest videos on the channel, under two minutes. It was made to answer one question that came up in the groups over and over: how do I know I'm drinking enough? My answer was to look, not to count glasses.
In this video
- [0:00] The "so many glasses a day" rule has kind of been debunked, I said. The easiest check is the colour of your urine, as long as you're not on a medication that changes it.
- [0:30] Dark yellow, amber or anything toward orange means you need more fluid. Clear or near-clear means you're probably plenty hydrated.
- [1:00] The contradiction I kept seeing online: drink lots of water and keep your electrolytes up. Every bathroom trip passes some electrolytes, so pushing both at once puts people on a hamster wheel (from the video).
- [1:00] Pale yellow, going somewhat regularly through the day, is the target. Going all the time, in volume, and clear may mean you're flushing enough electrolytes to give yourself keto-flu symptoms or cramps.
Watching this in 2026: the check that stuck
This is one of the few pieces of advice I gave in 2017 and repeated almost word for word later. In the 2018 basics video the hydration section is the same rule: pale yellow is right, clear is too much, dark yellow means drink something, probably water (video UygKGoP_BtA). Nine months and a lot of opinions later, I didn't change it.
I think it lasted because it's the kind of rule I like most. It's free, you can check it several times a day, and it adjusts itself to your size, the weather and how hard you trained. A fixed number of glasses can't do that.
The one caveat I gave in both videos still matters: some medications and supplements change urine colour. If yours does, the check doesn't work for you, and that's worth asking your pharmacist or doctor about.
The claim worth unpacking: the "hamster wheel"
My point was that water and electrolytes aren't two separate goals. Drink far more than you need and you pass more of what you're trying to keep. I said it as a warning, not as a measured fact.
The evidence pages don't hold a study that measures how much sodium or potassium extra water washes out on a keto diet, so I can't put a number on the hamster wheel. What the electrolytes page does have is the reason people lose more sodium early on. When insulin was infused into healthy men with blood glucose held steady, their kidneys excreted less sodium, potassium and phosphate (DeFronzo 1975). Run that the other way, with insulin lower on a low-carb diet, and you'd expect the kidneys to let more sodium go.
The page is also clear about what's missing: a PubMed search found no highly cited trial that directly measures that sodium loss under a ketogenic diet in adults. The mechanism comes from fasting studies and insulin studies. So the honest version is: early sodium loss on keto is well-reasoned, and over-drinking making it worse is my reasoning on top of that.
Keto flu, cramps and the first few weeks
I linked over-drinking to keto-flu symptoms and cramps (video RGfWR5jQNDQ). The one keto-flu paper on the evidence page is a content analysis of online posts: reported symptoms clustered in the first weeks and were mostly described as passing (Bostock 2020). That fits what I saw in the groups, but it can't tell you what caused any one person's symptoms.
In other videos I separated the causes: fatigue from not being fat adapted yet, and cramps from electrolytes (video 9r2Y74AnjUQ). Hydration sits next to the electrolyte side. If you're cramping and peeing clear all day, drinking less and salting your food is a reasonable first thing to look at before buying anything.
For reference, the US National Academies set adult sodium adequate intake at 1,500 mg a day and advise reducing intake above 2,300 mg; potassium adequate intake is 2,600 mg for women and 3,400 mg for men (NASEM 2019). Those numbers weren't set for people in the first weeks of keto, which is part of why this topic stays argued about.
When the simple check isn't enough
Urine colour is a check for generally healthy adults, and I said so in the video. A few groups should talk to their doctor about fluid and electrolytes before following any keto rule of thumb:
- People with kidney disease, who may be on a fluid or potassium limit.
- People on blood pressure medication, especially diuretics ("water pills"), which change how much water and sodium you pass.
- Anyone who is pregnant, since fluid and salt needs are part of prenatal care.
For everyone else, the rule from the video is still the rule.
Key points
- Look at the colour, don't count the glasses: pale yellow is the target.
- Dark yellow to orange means drink more; clear all day means you can probably ease off.
- Drinking far more than you need passes more electrolytes, which can feed cramps and keto-flu symptoms.
- Early sodium loss on low-carb has a known mechanism (lower insulin); the size of the over-drinking effect isn't measured on the evidence pages.
- Medications that change urine colour make the check useless; ask about yours.