Simple question that I can't get a straight answer on: how many carbs per day do I need to stay in ketosis? I see 20g on most sites but my friend says she eats 50g and stays in ketosis. Someone else told me it's different for everyone. What's the actual number?
Your friend is right — it IS different for everyone, but there's a reliable starting point.
The standard recommendation: 20g net carbs per day. Net carbs = total carbs minus fiber. This works reliably for almost everyone to get into and maintain ketosis, regardless of metabolism, activity level, or body size.
Why 20g and not more? It's conservative enough to account for individual variation. Some people do enter and maintain ketosis at 30-50g net carbs — these tend to be people who are very active, already lean, or have been fat adapted for years. But starting at 20g removes the guesswork.
How to find YOUR personal carb threshold: Start at 20g for 4-6 weeks until fully fat adapted. Then slowly increase by 5g per week while testing ketones with a blood meter. The level where your blood ketones drop below 0.5 mmol/L is your personal ceiling.
Important distinction many miss: the 20g limit refers to NET carbs (total minus fiber), not total carbs. Many vegetables have high total carbs but very low net carbs because of fiber content. A cup of spinach has about 1g net carb but 3-4g total carbs. Using total carbs instead of net carbs will make keto unnecessarily restrictive and eliminate vegetables you could actually eat.
Exception: some people are sensitive to sugar alcohols as well. If you're eating keto products with erythritol or xylitol and not losing weight, try counting those too.
Personal data point: I can maintain ketosis at 35g net carbs after 3 years. When I first started I needed strict 20g. Fat adaptation genuinely seems to increase carb tolerance over time. Your 50g friend is probably long-term adapted.
Also — the type of carbs matters a bit. 20g from leafy vegetables hits differently than 20g from a keto bar with processed ingredients. Whole food carb sources are less likely to spike insulin even at the same gram count.
So the short answer is: start at 20g net carbs, no exceptions, until I'm fat adapted, then I can test my personal threshold. Got it. This actually makes complete sense now. Thank you!