PSMF FAQ
The numbers below come from the Cleveland Clinic protocol described by Chang and Kashyap (2014). Your doctor may set different targets for you.
What does PSMF stand for?
Protein sparing modified fast. You eat lean protein and a few low-starch vegetables and keep calories under 800 a day. The protein limits how much muscle you lose.
How many calories do I eat?
Under 800 kcal a day during the intensive phase.
How much protein?
1.2 to 1.5 g per kg of ideal body weight per day. Cleveland Clinic uses 1.5 g/kg. It is based on ideal body weight, not current weight. The protein calculator does the math.
How many carbs?
Under 20 to 50 g a day, mostly from two servings of low-starch vegetables plus lettuce.
Can I eat any fat?
The protocol allows no added fat: no butter, oil, nuts, seeds or dips. The fat you get comes from the protein foods themselves, which the protocol limits to under 3 g of fat per ounce. The review notes that this fat probably helps keep the gallbladder emptying, which lowers gallstone risk compared with very-low-fat liquid diets. The meal plan page shows how much fat a sample day has.
Do I need supplements?
The protocol uses a daily multivitamin plus potassium, calcium, magnesium and sodium. Get the potassium and magnesium doses from your doctor.
How long can I stay on it?
In the Cleveland Clinic protocol the intensive phase lasts up to about 6 months, with medical checks throughout. It is followed by 6 to 8 weeks of refeeding.
How much weight will I lose?
The review reports typical losses of 1 to 3 kg a week, with more in the first 2 weeks. Much of the early drop is water.
What is refeeding?
The 6 to 8 weeks after the intensive phase, when you add carbohydrate and fat back slowly and cut protein down. Skipping it makes regain more likely.
Is PSMF safe?
For the right person, with a doctor watching, clinics have used it for decades. It is not safe for everyone. Read the safety page for who should not do it and the symptoms that mean stop.
Can I do PSMF without a doctor?
This site’s advice is no. The diet can change blood sugar, blood pressure and electrolytes within days, and the clinical protocol includes an ECG and regular blood work.
Can I exercise on PSMF?
Ask your doctor. Dizziness when standing is a listed side effect, and energy is low, so hard training can be risky early on.