Methodology

How we choose topics

We start from what people trying the ketogenic diet really ask: what do I eat, what do I avoid, what is true and what is a myth. We do not chase the trend of the week.

How we weigh the evidence

• First, systematic reviews and meta-analyses.

• Then, randomised clinical trials.

• Then, observational studies, with a clear word on where they fall short.

• Animal and laboratory studies are mentioned only as indications, never as proof for humans.

When the data are few, short-term or conflicting, we say so.

How a text is reviewed

• The author writes the text and adds the sources.

• The editor checks that it is clear, that the sources hold up and that it follows the Editorial policy.

• If the text concerns health, a health professional checks it before it is published.

• Every change stays in the revision history.

Updates

When the data change, we re-read the texts. Every page shows when it was last updated.

Nutrition data for foods

For every food in the database we hold nine values per 100 grams: energy, fat, saturated fat, carbohydrates, sugars, fibre, polyols, protein and salt. Next to them we show where the data came from and when they were recorded.

Generic foods come from the USDA FoodData Central database and branded products from Open Food Facts. Some we enter by hand, from product labels or from our own team. The “Data sources” page gives the source and licence of every data set.

Net carbs

We calculate net carbs with the same rule for every food: carbohydrates minus polyols. Fibre is subtracted only when the source counts it inside the “total” carbohydrates. The result never goes below zero.

The distinction is needed because in American databases (USDA) “total” carbohydrates include fibre, so we subtract it. On European Union labels and in Open Food Facts carbohydrates are already given without fibre, so we do not take it off again. For every food we record which of the two conventions its source follows.

For business products we take the values from the product’s EU label, as the business itself declares them: net carbs = carbohydrates minus polyols. We do not subtract fibre, since on an EU label it is not part of the carbohydrates. The keto label uses the same thresholds as for foods.

Keto label

The label comes from the net carbs per 100 grams, rounded to one decimal place:

• Up to 5.0 grams: “Keto: yes”.

• From 5.1 to 15.0 grams: “Keto: in moderation”.

• Above 15.0 grams: “Keto: no”.

By “in moderation” we mean the food fits, but you watch how much of it you eat. When our team sets the label by hand instead of following the rule, we note it on the food’s page. No food is published before a person has checked its label.

Servings

For some foods we also give the values per serving, e.g. “1 medium egg” or “1 tablespoon”. The grams per serving are a guide, because every piece weighs something different.

Errors and corrections

Every food page has a “Report an error” button. Our team looks at every report; the correction is made openly, with a new update date.

Limits

The data refer to generic foods rather than specific brands, unless a product label is given as the source. Variety, ripeness and cooking change the numbers. None of this is medical advice.

Tools

The tools (calories, macros, net carbs, electrolytes, keto flu) show on their own page the formula they use, their sources and their limits. Calories and macros are calculated with the Mifflin-St Jeor equation. We give no number to people under 18, with a body mass index below 18.5, or during pregnancy or breastfeeding. The result, for its part, never goes below 1,200 calories for women and 1,500 for men. The calculation runs on your own device.