What ketosis is, why NooKeto uses it, and the honest case for and against — in plain language.
Your body has two primary fuel systems. The default runs on glucose — broken down from carbohydrates. The alternative runs on ketone bodies — produced by the liver from fatty acids when glucose is scarce.
When you restrict carbohydrates below roughly 20–50g of net carbs per day (net carbs = total carbs minus fibre), your liver begins converting stored and dietary fat into three ketone bodies: beta-hydroxybutyrate (BHB), acetoacetate, and acetone. Your cells — including brain cells — then use these ketones for energy instead of glucose.
This metabolic state is called nutritional ketosis. It is not the same as diabetic ketoacidosis (a dangerous condition in uncontrolled type 1 diabetes where ketone levels rise 5–10× higher than nutritional ketosis). In nutritional ketosis, blood ketone levels typically sit between 0.5–3.0 mmol/L — a safe, regulated range.
NooKeto uses 20g net carbs per day as the upper limit. This number is deliberately conservative — most people will reliably enter and maintain ketosis at this level regardless of individual variation in carbohydrate tolerance.
Why not 50g? Some people can maintain ketosis at higher levels, but 20g provides a margin of certainty. It removes the guesswork: you don't need to measure blood ketones daily to know you're in ketosis if you're consistently at or below 20g net.
In practice, these 20g come almost entirely from leafy greens, berries (in small portions), nuts, and the incidental carbs in eggs and other whole foods. There's no room for bread, rice, pasta or sugar — but there's ample room for nutrient-dense vegetables.
The brain is often cited as requiring glucose, and it's true that certain brain cells always need some glucose. But the brain can derive up to 60–70% of its energy from ketones when they're available — and there's reason to believe this is advantageous:
Evidence note. The cognitive benefits of ketosis are supported by animal research and emerging human trials, but large-scale, long-term RCTs in healthy adults are still limited. What we can say: ketones are a viable brain fuel, subjective cognitive clarity is widely reported, and the mechanistic rationale is strong. What we cannot yet say: that ketosis definitively prevents cognitive decline in all populations. Sources on the research page.
On a ketogenic diet, fat becomes your primary energy source (typically 65–75% of calories). This makes fat quality critically important — you're eating a lot of it.
NooKeto's fat hierarchy:
What's excluded: seed oils (sunflower, canola, soybean, corn) — high in omega-6, oxidation-prone at cooking temperatures, and absent from any ancestral dietary pattern. Also excluded: margarine, processed "keto" products with ingredient lists longer than three items.
Ketogenic eating tends to work well for people who:
What the evidence shows — honestly. Short-to-medium-term keto trials (up to 2 years) show clear benefits for weight loss, blood sugar control, and triglyceride reduction. Evidence for cognitive benefits is mechanistically strong but clinically early-stage. Very long-term data (10+ years) on ketogenic diets in healthy adults simply doesn't exist yet — the diet hasn't been mainstream long enough. NooKeto hedges this uncertainty by keeping food quality extremely high and monitoring blood markers regularly. Full citations on the research page.
See how NooKeto selects foods for the brain, not just for macros: Nootropic Nutrition. Understand the MIND-diet connection: The MIND Connection. Or dive into the evidence: The Research.
The 7-day on-ramp gives you everything you need — shopping list, daily meals, and what to track.
Start here — your first 7 days