Diet Labels Decoded: A Plain-Language Glossary of Eating Plan Terms

Whole-food diet

An eating approach centered on minimally processed foods — vegetables, fruits, whole grains, legumes, nuts, and lean proteins — with limited refined ingredients. The emphasis is on nutrient density and the preservation of naturally occurring fiber, vitamins, and phytochemicals.

Plant-based diet

A broad term for eating patterns that prioritize foods derived from plants. It does not necessarily mean vegan; many plant-based frameworks allow modest amounts of animal products while making plants the dietary foundation.

Ketogenic (keto) diet

A very low-carbohydrate, high-fat eating pattern designed to shift the body's primary fuel source from glucose to ketone bodies, a state called ketosis. Carbohydrate intake is typically restricted to roughly 20–50 grams per day, though specific targets should be discussed with a clinician.

Glycemic index (GI)

A scale from 0 to 100 that ranks how quickly a carbohydrate-containing food raises blood glucose compared with pure glucose. Low-GI diets prioritize foods that produce a slower, smaller rise in blood sugar.

Flexitarian diet

A predominantly plant-based eating pattern that occasionally includes meat or fish. It offers flexibility compared to strict vegetarianism, making it accessible for people transitioning away from heavy meat consumption.

Mediterranean diet

An evidence-backed pattern based on the traditional eating habits of countries bordering the Mediterranean Sea. It emphasizes vegetables, legumes, whole grains, olive oil, fish, and moderate amounts of dairy, with red meat consumed infrequently.

FODMAP

An acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols — short-chain carbohydrates that are poorly absorbed in the small intestine. A low-FODMAP elimination diet is a clinical protocol primarily used to identify food triggers in irritable bowel syndrome (IBS).

Elimination diet

A structured protocol that removes specific foods or food groups suspected of causing adverse reactions, then systematically reintroduces them to identify triggers. It is a diagnostic tool and should be carried out under professional guidance.

Intermittent fasting (IF)

A broad category of eating schedules that cycle between defined periods of eating and fasting. Common protocols include the 16:8 method (16 hours fasting, 8-hour eating window) and the 5:2 pattern (normal eating five days, reduced intake two days per week).

Caloric density

The number of calories contained per unit weight of a food, typically expressed as calories per gram. Low-caloric-density foods (such as vegetables and broth-based soups) provide more volume per calorie, which can support satiety.

Anti-inflammatory diet

A general dietary approach that emphasizes foods associated with reduced systemic inflammation — such as fatty fish, berries, leafy greens, and olive oil — while limiting ultra-processed foods, refined sugars, and trans fats. It is a framework rather than a single defined protocol.

DASH diet

Dietary Approaches to Stop Hypertension — a clinically studied eating plan developed to help manage blood pressure. It emphasizes fruits, vegetables, low-fat dairy, whole grains, and lean proteins, while limiting sodium, saturated fat, and added sugars.