Based on Prevention is Cure, Episode #49, featuring Prof. Grant Schofield Ketogenic diets still get eye-rolls in clinical settings, but according to Prof. Grant Schofield, the science behind ketosis is less about a fad diet and more about restoring a metabolic cycle humans evolved with and have largely lost. Here’s what the research actually shows.
What Is Ketosis? (And Why It’s Not the Same as “Low-Carb”) Ketosis and a low-carb diet aren’t identical. Ketosis is a distinct metabolic state, the body’s “cleaning” phase, as opposed to its “growth” phase.
- Growth phase: triggered by glucose and protein in the blood, mildly inflammatory, and essential for cell division and building tissue.
- Ketosis (cleaning) phase: cells stop dividing and switch on self-maintenance processes, including autophagy, mitophagy, and apoptosis, that clear out damaged cellular components.
The signal for this cleaning phase is ketones (beta-hydroxybutyrate, acetoacetate, and acetone), produced from fat when the body senses a food shortage. Schofield argues that ancestrally, humans cycled between these two states daily. Modern eating patterns, by contrast, keep most people locked permanently in the growth phase, which he calls a root cause of chronic disease.
Insulin Resistance and Metabolic Syndrome, Explained Insulin is the hormone that clears glucose from the blood after eating carbohydrate-heavy foods (bread, pasta, rice, sugar). While insulin is up, fat-burning and ketone production switch off.
Metabolic syndrome is diagnosed when someone has three or more of the following: high waist circumference, high triglycerides, high blood pressure, low HDL cholesterol, and insulin resistance. Schofield cites research suggesting roughly a third of New Zealanders, Australians, and Americans meet this threshold, while fewer than 5% of people can even explain what insulin does. That gap, he argues, is a major reason chronic disease remains so poorly managed.
Does the Ketogenic Diet Actually Work for Weight Loss? Yes, and better than most alternatives, according to head-to-head trials Schofield references (including the DIETFITS and A TO Z diet studies). Low-carb/ketogenic diets consistently produce the most weight loss with the least regain compared to Mediterranean and low-fat plant-based approaches, without requiring calorie restriction.
That said, long-term adherence is still the biggest challenge across every diet type, which is part of why GLP-1 medications have surged in popularity as a pharmacological workaround for a food environment that overrides natural appetite regulation.
Beyond Weight Loss: Where Keto Shows the Strongest Evidence Epilepsy: the original clinical use of the ketogenic diet since the 1920s. It reduces seizure frequency in roughly half of patients with drug-resistant epilepsy by giving the brain an alternative fuel source when glucose metabolism fails.
Type 2 diabetes: cutting dietary glucose directly lowers blood sugar and insulin, and sustained carbohydrate restriction can put diabetes into remission, as shown by clinicians such as Dr. David Unwin.
The Emerging Frontier: Mental Health and Cancer Schofield is careful to separate established science from promising-but-early research:
- Metabolic psychiatry: Small studies and case reports (including the Baszucki Group’s funding into “metabolic mind” research) suggest ketogenic diets may help with schizophrenia, bipolar disorder, and even anorexia nervosa. One feasibility study saw 16 of 18 participants lose their clinical diagnosis. Schofield stresses this is frontier science, not yet proven in randomized trials.
- Cancer metabolism: Cancer cells often can’t perform normal oxidative metabolism (the Warburg effect) and rely on glucose fermentation. Fasting-mimicking ketogenic protocols, like Dr. Matthew Phillips’ regimen for glioblastoma patients, may metabolically starve tumor cells and increase sensitivity to chemotherapy and radiotherapy.
The Dark Side of Keto Schofield is blunt about keto’s downsides:
- “Keto flu”: fatigue, dizziness, and low blood pressure in the first few days as sodium and potassium are flushed out; easily managed with electrolytes.
- “Dirty keto” culture: fat bombs and bulletproof coffee aren’t the point; whole-food quality still matters.
- It’s tribal: evangelism from people who’ve fixed a health issue with keto has fueled skepticism among clinicians.
- Not a forever diet: Schofield himself cycles in and out of ketosis rather than staying keto year-round, and doesn’t recommend it for people training at high volume or intensity, where carbohydrate is a more practical fuel.
Key Takeaway The evidence doesn’t suggest everyone needs to live in ketosis permanently. Schofield’s core argument is that
occasional cycling into ketosis, through carbohydrate restriction, fasting, or both, restores a metabolic flexibility most modern diets have erased, with the strongest benefits for people managing insulin resistance, epilepsy, or specific metabolic conditions.
Listen to the full conversation: Prevention is Cure, Episode #49, “Keto, what they don’t tell you” Learn more about Prekure:
prekure.com/programmes/ 
