Today, health-conscious consumers’ demand for low-fat or fat-free food products to prevent obesity and coronary heart diseases encourages food scientists to probe alternatives for fat in these systems. Fat has very important functions and its removal causes serious quality problems. Biopolymers can be utilized to modulate the textural and sensory characteristics of fat-replaced products. The largest numbers of biopolymers are hydrocolloids in which their functional properties, such as textural, viscosifying, and mouth feel, allow them to mimic the sensory and flow characteristics in a manner like fat. Herein, we consider how biopolymers, concentrating on novel food hydrocolloids, which can be used to design fat-replaced systems. Also, some of the biopolymer applications as fat replacers within foods, such as cheese, ice cream, sauce, and yogurt, are highlighted. Regarding this overview, healthful products should be methodically designed to encourage consumers to choose a fat-replaced product.