Yogurt is a nutrient dense food and plain yogurt has a low energy density
Energy density is the amount of energy – or calories – per gram of food. Lower energy density foods provide fewer calories per gram than higher energy density foods. Hence low energy dense foods allow satisfying portions with a relatively low calorie content to be eaten.
Compared with other foods, plain low-fat yogurt has a low energy density of 0.6–1.5 kcal/g.
British Nutrition Foundation. What is energy density?