Based on the gathered data, it has been concluded that onion can be helpful in the prevention and treatment of dyslipidemia, high blood pressure, diabetes mellitus, and obesity as metabolic syndrome disorders and subsequently CVDs on account of anti-oxidant, anti-inflammatory, and vasodilatory properties, increasing insulin release and response, reduction of cholesterol and glucose absorption, modulating the metabolism of lipids and carbohydrates, and inhibition of adipogenesis. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.