How It Works

Methodology, sources, and editorial process

Overview

AllowedOn classifies foods against the published guidelines of 25 dietary frameworks. Each food receives one of three classifications per diet: Allowed, Not Allowed, or Limited. Classifications are derived through a structured, rule-based process — not by user vote, not by AI guesswork, and not by opinion. This page documents the full methodology, the sources we draw on, worked examples for three real foods, and the process for reporting and applying corrections.

The Classification Process

Each food goes through the same four-step evaluation against each diet:

  1. Identify the diet's core lever. Every dietary framework sorts foods on a specific axis. Keto sorts on net carbohydrate content. AIP sorts on whether a food belongs to one of its eight elimination categories. Vegan sorts on animal-derived content. DASH sorts on sodium and the daily serving targets for fruits, vegetables, dairy, grains, and protein. Each diet has its own lever, and the classification of any specific food depends on which side of that lever the food falls on.
  2. Categorize the food. Foods are placed into one of nineteen broad categories (Vegetables, Fruits, Grains, Dairy, Meat & Poultry, Seafood, Legumes, Nuts & Seeds, Sweeteners, Beverages, Condiments, Confectionery, Fats & Oils, Spices & Seasonings, Soups & Broths, Snacks, Protein, Flours & Grains, Dairy Alternatives) based on their primary composition. Category placement matters because many diet-level rules apply at the category level — for example, AIP's nightshade exclusion applies to all nightshade vegetables regardless of which specific vegetable is being evaluated.
  3. Apply the diet's rules to the food. Each diet has a set of rules that we encode programmatically. The rules combine the diet's core lever (step 1) with category-specific exceptions and individual food overrides where needed. The output is the food's classification: Allowed, Not Allowed, or Limited.
  4. Generate the explanation. The classification is accompanied by a written explanation specific to the diet's lever and the food's category. The explanation describes why the food received its classification, what specific aspect of the diet's rules drove the result, and (for Limited or Not Allowed foods) what alternatives or workarounds typically apply.

Three Worked Examples

Rather than describe the process abstractly, here are three real foods, evaluated against three different diets, with the reasoning shown step by step.

Example 1 — Acorn Squash on Keto (Not Allowed)

Diet's core lever: net carbohydrate content, measured against a daily ceiling of roughly 20 to 50 grams to maintain ketosis.
Food category: Vegetables.
Category-level rule on keto: non-starchy vegetables fit; starchy vegetables and winter squashes typically do not.
Food-level evaluation: a one-cup serving of cooked acorn squash contains roughly 15 grams of net carbohydrates — close to or above an entire daily allowance on stricter keto, and a substantial fraction even on the looser end.
Result: Not Allowed. The classification is driven by carb density, not by anything wrong with the food itself, and the page explanation directs readers to non-starchy vegetable substitutes that fit the same culinary role.

Example 2 — Sardines on Mediterranean (Allowed)

Diet's core lever: frequency in the traditional Mediterranean eating pattern, with fatty fish recommended at least twice a week.
Food category: Seafood.
Category-level rule on Mediterranean: fish and seafood — especially small fatty fish — are a foundational category eaten several times per week.
Food-level evaluation: sardines are a small, fatty, short-lived fish, low on the food chain (which keeps mercury low), high in EPA and DHA omega-3s, and one of the foods most directly recommended in the published Mediterranean dietary literature.
Result: Allowed. The classification is driven by the diet's explicit recommendation of fatty fish, and the page explanation notes that canned sardines retain nearly all of the omega-3 content of fresh fish at a fraction of the cost.

Example 3 — Banana on Low-FODMAP (Limited)

Diet's core lever: fermentable carbohydrate content, measured in the FODMAP subgroups (fructans, GOS, lactose, excess fructose, polyols).
Food category: Fruits.
Category-level rule on low-FODMAP: fruits vary widely; most FODMAP foods are dose-dependent rather than universally banned.
Food-level evaluation: Monash University's published FODMAP testing shows that an unripe (firm, slightly green) banana is low-FODMAP at a normal serving size, while a ripe banana exceeds the threshold for fructans at the same portion. The food is the same; the ripeness changes the answer.
Result: Limited. The page explanation notes that this is a textbook example of why low-FODMAP eating uses a dose-dependent threshold rather than a binary in/out list, and points readers to Monash's published serving sizes for accurate portion guidance.

Nutritional Data

AllowedOn displays per-food nutritional information sourced from the USDA FoodData Central database, maintained by the U.S. Department of Agriculture. Nutrition values (calories, protein, fat, carbohydrates, fiber, sodium, potassium, phosphorus, and other micronutrients) are reported per 100 grams using USDA Standard Reference and Foundation food entries. This data provides the factual basis for understanding why a food receives a particular classification — for example, the net carb count that determines keto compliance, or the sodium content that drives DASH and low-sodium classifications.

Nutritional data is cached at build time and updated periodically. It reflects generic, unbranded versions of each food. Specific branded products may differ from these values.

Data Sources

Classifications are built from publicly available, widely recognized dietary guidelines and the published work of researchers and clinicians who have shaped each framework. The main sources by diet:

  • Whole30 — the official Whole30 program rules and ingredient list as published by Melissa Urban and the Whole30 organization.
  • Keto — published clinical literature on the ketogenic diet, including its origin as a treatment for pediatric epilepsy and the more recent metabolic and weight-loss research.
  • Paleo — Loren Cordain's foundational work and the broader paleo literature from researchers including Robb Wolf and Mark Sisson.
  • Mediterranean — the Seven Countries Study (Ancel Keys), the Lyon Diet Heart Study, and the PREDIMED trial published in the New England Journal of Medicine in 2013.
  • DASH — the National Heart, Lung, and Blood Institute (NHLBI) DASH eating plan and the original DASH trial published in the New England Journal of Medicine in 1997.
  • Low-FODMAP — Monash University's published FODMAP food database and the clinical literature on irritable bowel syndrome and FODMAP intervention.
  • AIP — the published Autoimmune Protocol literature, including Sarah Ballantyne's foundational work on the protocol's elimination and reintroduction phases.
  • Vegan and Vegetarian — guidelines from the Vegan Society, the Vegetarian Society, and position papers from the Academy of Nutrition and Dietetics on plant-based diets.
  • Gluten-Free — published celiac disease and non-celiac gluten sensitivity research, plus the FDA labeling rule defining gluten-free as 20 parts per million or less.
  • Kosher — traditional kashrut law as documented by recognized certifying agencies including the Orthodox Union (OU), OK Kosher, Star-K, and Kof-K.
  • Halal — Islamic dietary law and the published guidance of major halal certifying bodies including IFANCA, JAKIM, and HFA.
  • Kidney-Friendly — National Kidney Foundation guidelines and the published renal nutrition literature on sodium, potassium, phosphorus, and protein restriction in chronic kidney disease.
  • Other diets — for diets without a single canonical authority (Anti-Inflammatory, Whole-Food, Sugar-Free, etc.), classifications are built from the consensus published literature and from the practical guidelines used by the practitioners and clinicians who write about these patterns.

AllowedOn does not conduct original laboratory analysis or clinical research. Classifications reflect how a food is generally understood to align with a diet's published criteria — not a measurement of the food's specific nutritional content in a particular brand or batch.

What "Limited" Actually Means

Limited is not a hedge — it carries specific meaning. A food is classified as Limited when at least one of the following is true:

  • The food is dose-dependent on the diet. Common in low-FODMAP, where most foods are tolerated at small servings and become problematic at larger ones, and in keto/low-carb, where carb content matters per serving rather than per food.
  • Brand and formulation drive the answer. Common in processed categories like sauces, condiments, dairy alternatives, and protein bars, where the same product name can have very different ingredient lists across brands.
  • Preparation method changes the result. Common in gluten-free (cross-contamination risk), kidney-friendly (potatoes can be leached to lower potassium), and raw-food (cooked vs. uncooked).
  • The food sits on a doctrinal boundary. Common in religious diets — for example, ghee on AIP (technically dairy-derived but allowed by some practitioners), or stevia on sugar-free (non-caloric but excluded by stricter versions).

Each Limited classification on the site explains which of these conditions applies and what to do about it.

Editorial Standards

AllowedOn operates under three editorial commitments that we will not compromise on:

  • Independence from commercial interests. Classifications are not influenced by advertisers, food brands, supplement companies, or diet program sponsors. The site does not accept payment for classifications, favorable listings, or placement in any section. Advertising on the site (when present) is served by independent ad networks and has no editorial influence.
  • Distinction between evidence and consensus. Where the underlying evidence for a diet is strong (for example, the PREDIMED trial for the Mediterranean diet), the content says so. Where the evidence is weaker or contested (for example, the alkaline diet's pH claims, or some of the specific mechanisms claimed for raw food), the content says so as well. We do not present contested claims as settled, even when doing so would make the content easier to read.
  • No medical advice. AllowedOn is a reference site, not a clinical service. We do not diagnose, treat, or recommend dietary changes for individuals. People managing medical conditions through diet should work with a registered dietitian or physician.

Limitations We Want Readers to Know About

AllowedOn has real limits, and we'd rather state them clearly than have readers discover them by accident:

  • Product formulations vary. A food classified as Allowed in its standard form may not be Allowed in all commercial versions. Flavored, sweetened, or processed varieties often contain additional ingredients that change the classification. The label is always the final source of truth for any specific product.
  • Some diets do not publish exhaustive food lists. Mediterranean, anti-inflammatory, and whole-food eating are patterns rather than rule lists, so classifications for these diets reflect applied judgment based on the diet's published principles. Reasonable practitioners may interpret edge cases differently.
  • Individual needs differ. A food classified as Allowed on a diet may still be inappropriate for a specific person due to allergies, intolerances, medical conditions, or medication interactions. The classification answers the diet question, not the individual one.
  • Guidelines evolve. Dietary frameworks update their rules over time, especially the research-driven ones. Monash regularly retests foods and updates the FODMAP database. The Whole30 program has adjusted its rules. Newer evidence has softened some of the original DASH recommendations on dairy fat. We aim to reflect current guidelines but cannot guarantee real-time accuracy on every food.
  • This is not medical advice. AllowedOn is informational. It is not a substitute for guidance from a qualified healthcare provider, registered dietitian, or physician.

Corrections Workflow

Errors happen. When a reader believes a classification is wrong, the process for correcting it is:

  1. Submit the correction by email to hello@allowedon.com, or via the Contact page. Include the specific food, the diet, the current classification, the classification you believe is correct, and a source or reasoning to support the change.
  2. Initial review. We check the request against the relevant published guidelines for the diet in question. For research-driven diets (FODMAP, DASH, Mediterranean), we check the most recent published source. For religious diets, we check whether the question concerns a point of doctrinal disagreement or a clear rule.
  3. Decision. If the correction is supported by the guidelines or by published evidence, we update the classification and the explanation. If the request reflects a doctrinal disagreement (something the diet itself debates internally), we update the explanation to acknowledge both positions rather than picking a side. If the request is not supported, we reply explaining why.
  4. Site update. Approved corrections are applied at the next site rebuild, and the change carries through to all pages where that food appears.

We do not have a public correction log yet, but we maintain an internal record of all reviewed correction requests.

Update Schedule

AllowedOn is reviewed on the following cadence:

  • Reader-reported corrections — reviewed within a few business days of receipt.
  • Diet-level rule changes (such as updates to the Monash FODMAP database, or new editions of major program guidelines) — reviewed when the changes are published, with affected classifications updated at the next site rebuild.
  • Full editorial review of each diet's content — performed annually to catch drift, update outdated phrasing, and incorporate new research.

Editorial Independence

AllowedOn operates independently of diet programs, food manufacturers, supplement companies, and clinical organizations. We have no commercial relationships that influence classifications. Advertising on the site (when present) is served through independent ad networks and is not related to the editorial content. Sponsored content, paid classifications, and pay-for-placement do not exist on this site, and we will not accept them in the future.