PET scans of areas of their brains activated by thirst showed reactions -- particularly in the cingulate cortex. In the elderly, drinking a much smaller volume of water is needed to cause that area of brain activation to subside, said Egan, who is an expert on neuro-imaging.
What is Nutrient Density? It is a measure of the nutrients provided per calorie of food, or the ratio of nutrients to calories (energy). Foods that supply generous amounts of one or more nutrients compared to the number of calories they supply are called nutrient dense.
Nutrient Density vs. Energy Density. Nutrient-dense foods contain a lot of essential nutrients per serving, while energy-dense foods are those that have a lot of calories in a serving. Foods that are very high in fat or sugar are energy dense. However, some foods are both nutrient dense and energy dense, such as cheese, meat and nuts.