The Western pattern diet is a modern dietary pattern that is generally characterized by high intakes of pre-packaged foods, refined grains, red meat, processed meat, high-sugar drinks, candy and sweets, fried foods, industrially produced animal products, butter and other high-fat dairy products, eggs, potatoes, corn (and high-fructose corn syrup), and low intakes of fruits, vegetables, whole grains, pasture-raised animal products, fish, nuts, and seeds.
Dietary pattern analysis focuses on overall diets (such as the Mediterranean diet) rather than individual foods or nutrients. Compared to the "prudent pattern diet", which has higher proportions of "fruit, vegetables, whole grains, and poultry", the Western pattern diet is associated with higher risks of cardiovascular disease and obesity.
This diet is "rich in red meat, dairy products, processed and artificially sweetened foods, and salt, with minimal intake of fruits, vegetables, fish, legumes, and whole grains." Various foods and food processing procedures that had been introduced during the Neolithic and Industrial Periods had fundamentally altered 7 nutritional characteristics of ancestral hominin diets: glycemic load, fatty acid composition, macronutrient composition, micronutrient density, acid-base balance, sodium-potassium ratio, and fiber content.
In 2006 the typical American diet was about per day, with 50% of calories from carbohydrates, 15% protein, and 35% fat. These macronutrient intakes fall within the Acceptable Macronutrient Distribution Ranges (AMDR) for adults identified by the Food and Nutrition Board of the United States Institute of Medicine as "associated with reduced risk of chronic diseases while providing adequate intakes of essential nutrients," which are 45–65% carbohydrate, 10–35% protein, and 20–35% fat as a percentage of total energy. However, the nutritional quality of the specific foods comprising those macronutrients is often poor, as with the "Western" pattern discussed above.