This document discusses fat replacers, which are ingredients that can substitute for fats and oils in foods while providing fewer calories and similar textures. It describes different types of fat replacers such as those based on fat, proteins, or carbohydrates. Fat replacers are water-dispersible compounds that mimic the sensory qualities of fat. They can help with weight loss and reducing risk of diseases by allowing people to enjoy fatty foods less frequently while controlling calorie intake. The document provides an example of using whey protein to create a lower-fat ice cream for someone on a diet.