Defined by one rule: no consumption of animal flesh. Unlike veganism, vegetarianism permits animal by-products that don't require slaughter. The most common sub-types are Lacto-Ovo (dairy + eggs), Lacto (dairy only), and Ovo (eggs only).
An omnivorous diet — the most inclusive dietary framework. It encompasses everything in the plant kingdom, all animal by-products, and animal flesh of all kinds. By definition, it has zero inherent structural restrictions beyond cultural taboos and legal prohibitions.
Animal products deliver heme iron (15–35% absorption vs. 2–20% for plant iron), complete proteins with PDCAAS scores of 1.0, and naturally occurring B12 — removing the need for supplementation across all three.
Complete abstention from all animal products and derivatives — whether or not the animal was killed in the process. Honey, beeswax, and dairy are excluded. Relies entirely on the plant, fungi, and algae kingdoms.
Vitamin B12 cannot be reliably obtained from an unfortified plant-based diet. Vegans must supplement or consume heavily fortified foods (plant milks, nutritional yeast) to prevent irreversible neurological damage. Additionally: iron should be paired with vitamin C to boost absorption; calcium from kale, tahini, and calcium-set tofu (not spinach — oxalates block absorption).
Defined by Islamic jurisprudence (Sharia). Halal (permissible) vs Haram (forbidden). Unlike other dietary systems, Halal governs not just what is consumed but how the animal was slaughtered: a single swift cut severing the trachea, esophagus, and both jugulars, by a sane adult Muslim reciting Bismillah — known as Zabiha.
✓ Permitted · ✗ Forbidden · ⚠ Conditional / verify source · * Zabiha slaughter required
| Category | Vegetarian | Non-Vegetarian | Vegan | Halal |
|---|---|---|---|---|
| Fruits & Vegetables | ✓ | ✓ | ✓ | ✓ |
| Grains & Legumes | ✓ | ✓ | ✓ | ✓ |
| Dairy | ✓ | ✓ | ✗ | ✓ |
| Eggs | ✓ | ✓ | ✗ | ✓ |
| Red Meat | ✗ | ✓ | ✗ | ✓* |
| Pork | ✗ | ✓ | ✗ | ✗ |
| Poultry | ✗ | ✓ | ✗ | ✓* |
| Fish / Seafood | ✗ | ✓ | ✗ | ⚠ |
| Honey | ✓ | ✓ | ✗ | ✓ |
| Gelatin | ⚠ | ✓ | ✗ | ⚠ |
| Alcohol | ✓ | ✓ | ✓ | ✗ |
| Blood / Blood Food | ✗ | ✓ | ✗ | ✗ |
* Halal requires Zabiha (ritual slaughter). ⚠ for Halal seafood varies by school of jurisprudence.