One of the first things that a low real income produces is malnutrition.

Here are some of the world's most nutrient-dense foods:
Salmon, Kale, Seaweed, Garlic, Shellfish, Potatoes, Liver, Sardines, Blueberries, Egg Yolks, Dark Chocolate

The 11 Most Nutrient-Dense Foods on the Planet

15 Foods That Boost the Immune System