Abstract Foods contain various substances which control the physiological functions of the body, modulating immune responses which is one among the important functions of foods. Immune functions are indispensable for defending the body against attack by pathogens or cancer cells and plays a pivotal role in the maintenance of health. The immune system is supported by the fragile balance that comes with a healthy lifestyle. Adequate sleep, exercise, and, of course, a healthful diet all contribute to maintaining the body’s system of defense against illnesses.The immune system acts to guard the host from infectious agents that exist within the environment and from other noxious insults. Nutritional deficiencies seem to weaken the immune system leading to increased disease and mortality. Extrinsic factors can adversely affect immune responses producing states of secondary immunodeficiency and a consequent increased risk of infections. After all, a healthy body and sane mind is all we would like to survive the challenges of this fast paced world. So it is important to take care of a healthy immune system. In addition to knowledge of foods which boosts immunity, it is also important to know the foods that should be avoided to maintain a healthy immune system. This study reviews the foods that can be avoided to maintain immunity and thus promote the immune system.