The sense of smell is important in the perception of the flavor of food and it affects several aspects of eating behavior, like appetite and food preferences, which have important implications for quality of life. Viral infections can severely impact the chemical senses. A cold or a flu can result in the loss of the sense of smell and subsequently impact eating behavior and the processing of flavor in the brain. So far, these were the most common causes of viral smell loss, but in the past 2 years, Covid-19 has emerged as a new and major viral cause for smell loss. Therefore, a large part of the population is confronted with the effects of smell loss on both perceptual and – likely - neural level. To illustrate this, we will present data from an ongoing longitudinal study on smell dysfunction in Covid-19 patients, showing the impact of changes in the sense of smell on quality of life in these patients Also, we will show how smell loss impacts eating behavior, measuring food preferences and adherence to dietary guidelines in a population of patients with smell dysfunction. Additionally, we will present data collected at the Smell and Taste Center in the Netherlands, showing the impact of smell loss due to viral infections of differences types of causes on the structure and functionality of the brain.