**1. Introduction**

Functional foods are significant for human health as it is a major source of essential nutrients and can be used as a food supplement [1]. Different fruits, vegetables, grains, fishes, dairy, and meat products are naturally considered as the major source of functional food, moreover, all these foods can provide nourishment to the host body (**Figure 1**) [2]. Studies suggested that, tea and chocolate are also the part of functional food due to the presence of active compounds in them [3]. Balanced diet plays a considerable role throughout the consumer's life, it is necessary for the individual's mental and physical health as it can maintain human body functions actively [4]. Functional food can positively affect the body of an organism, it can fulfill basic requirements of the body and protect the host body against different malnutrition diseases and can remove various harmful particles from the body [5]. Studies suggested that, functional food can be recognized as a food product, that can contribute to enhance the body's metabolic rate without affecting the normal functions of the body and can stabilize the physical appearance of the body [6]. In this recent era, functional foods are responsible to provide energy to the individual's body so that the growth and development of the body can proceed smoothly [7]. Functional food has

the potential to mediate immune-modulatory response and subsequently decrease the risk of cardiovascular complications, osteoporosis, obesity and cancer which results to promote health promising effects in the individual's body [8]. Some of the examples of functional foods are vitamins, fortified food, fiber, minerals, peanuts, fruits and grain seed.
