In the era of increasing unhealthy dietary and lifestyle habits, maintaining a healthy diet is really important to prevent a broad spectrum of diseases. Lifestyle diseases occur due to certain unhealthy daily habits (smoking, unhealthy diet, and physical inactivity) that lead to inappropriate relationships with the environment. The consumption of food in an improper quantity and lacking in quality can have adverse effects on an individual’s health. Diet can bring about certain changes in genes which can be studied in the areas of nutrigenomics, nutrigenetics, epigenetics, epigenomics, and transcriptomics. This can help us understand how genetic makeup responds to nutrition in terms of transcription and translation processes. In this review, the effect of nutrition on gene expressions related to lifestyle disorders such as metabolic syndrome, CVD, and asthma is discussed.