So, you’ve been eating keto or carnivore for a while… you feel amazing, your energy’s up, inflammation is down — but then your bloodwork comes back and your doctor freaks out.
Sound familiar? If so, this post is for you because it addresses the confusion caused by bloodwork anomalies that often arise for those who follow ultra-low carb diets like keto and carnivore.
Now, let’s talk about why certain blood test results often fall outside the “normal” range when you’re on a very low-carb diet, and why that’s not always a bad thing.
Fasting Glucose – Lower Than Normal
First up: fasting glucose.
On a standard American diet, normal fasting glucose is around 70 to 99 mg/dL. But many people on keto or carnivore see numbers in the 60s or even 50s — and that’s totally expected.
Why?
Because when you're running on fat and ketones, your need for blood sugar drops. Your body becomes metabolically flexible, relying less on glucose and more on fat for fuel.
This is called physiological hypoglycemia, and it’s not dangerous — especially if you feel great and aren’t experiencing symptoms like dizziness or weakness.
LDL Cholesterol – Often Elevated
Here’s the big one: LDL-C, or “bad cholesterol,” often goes up on keto or carnivore.
Doctors might panic if they see LDL over 130, but here’s what they’re not telling you:
LDL cholesterol isn’t just one thing — it comes in two patterns:
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Pattern A: Large, fluffy, buoyant LDL particles (generally benign)
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Pattern B: Small, dense, oxidized LDL particles (associated with heart disease)
Low-carb diets tend to increase Pattern A particles while reducing the harmful Pattern B. They also often raise HDL (the good cholesterol) and lower triglycerides — both great signs for heart health.
So instead of just looking at total LDL, you should ask for a lipoprotein particle test or ApoB measurement to get the full picture.
Anion Gap – Sometimes Elevated
Next: the anion gap — a calculation used to check for metabolic acidosis.
On keto or carnivore, especially early on, your anion gap may rise slightly due to the presence of ketones, which are acidic. This doesn’t mean you’re in danger — it’s a normal result of nutritional ketosis.
Your body adjusts over time, and unless you’re showing signs of diabetic ketoacidosis (which almost never happens outside of type 1 diabetes), this is usually nothing to worry about.
Low Electrolytes – Sodium, Chloride, Magnesium, and Potassium
Ultra-low-carb diets have a diuretic effect — you lose water weight fast, and with it, you lose electrolytes.
That’s why it’s common to see:
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Low sodium
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Low chloride
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Sometimes low magnesium or potassium
If you’re not supplementing with electrolyte-rich foods, bone broth, or mineral salts, these levels can drop — leading to fatigue, dizziness, or even heart palpitations.
Make sure you’re replenishing electrolytes daily on keto or carnivore. It’s not just about avoiding the “keto flu” — it’s essential for healthy blood pressure, muscle function, and hydration.
Uric Acid and BUN – Slightly Elevated
Some people also see elevated uric acid and/or blood urea nitrogen (BUN) on high-protein versions of low-carb diets.
Why?
You're breaking down more purines from meat and producing more urea as a natural byproduct of protein metabolism.
These values usually normalize over time and don’t automatically indicate kidney damage, especially if your creatinine and eGFR are normal.
But yes — if you're concerned, it’s always good to check with a provider who understands low-carb physiology.
Liver Enzymes – Mixed Results
Liver enzymes like ALT and AST might shift slightly on low-carb diets, especially during weight loss, when your liver is working overtime processing fat and detoxifying.
In most cases, these levels normalize after your body adjusts — and some people even see liver markers improve, especially if they started with non-alcoholic fatty liver.
Keeping a Proper Perspective
The truth is that standard lab reference ranges are based on populations eating high-carb, grain-based diets — not people running on fat and ketones.
If you’re feeling great, losing fat, gaining energy, and your triglycerides are low and HDL is high — you’re probably on the right track.
Just make sure you're working with a provider who understands low-carb physiology, and not one who tries to prescribe statins as a knee-jerk reaction just because your LDL nudged over 130.
Drop your questions below — I’ll see you in the comments!
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