Understanding How Does Smell Play a Role in Appetite and Taste

January 10, 2026 •

4 min read

Studies have shown that up to 1 in 10 Americans may have a smell or taste disorder, yet few seek help, often misunderstanding the profound connection between the two senses. This critical relationship is central to explaining how does smell play a role in appetite and taste, and it profoundly impacts our eating behaviors and enjoyment of food.

Quick Summary

Flavor is a combined sensation of taste and smell, with aromas triggering physiological responses that influence hunger and cravings. The brain integrates olfactory and gustatory signals, creating a unified perception. Smell can stimulate or reduce appetite and is key to enjoying complex flavors beyond the five basic tastes.

Key Points

Flavor is a Multisensory Experience: Your perception of a food's flavor is primarily a combination of taste and smell, not just the basic qualities detected by your tongue.
Two Olfactory Pathways : Odors are perceived via two routes: orthonasal (inhaling external aromas) and retronasal (volatiles from chewing reaching the nasal cavity from the back of the throat), which is key to flavor perception.
Appetite is Triggered by Smell: Food aromas activate neurological pathways connected to the limbic system (memory/emotion) and hypothalamus (hunger control), stimulating appetite even when not physically hungry.
Physiological Responses are Primed: The smell of food initiates cephalic phase responses, such as salivation and hormone release, preparing the digestive system for the meal.
Losing Smell Affects Taste and Safety: Anosmia (loss of smell) drastically reduces the enjoyment of flavor, makes food taste bland, and removes the critical safety warning for spoiled food.
Aroma Influences Cravings and Choices: Learned associations and conscious or subconscious exposure to food aromas can increase specific cravings and influence your food choices.

The Interplay of Olfaction and Gustation

While often used interchangeably, taste and flavor are distinct senses. Taste, or gustation, is limited to the five basic qualities: sweet, sour, salty, bitter, and umami, detected by taste buds on the tongue. However, flavor is a much richer, multisensory experience that relies heavily on smell, or olfaction. Our perception of a strawberry's complete flavor, for instance, comes not just from its sweetness but from the volatile compounds released during chewing that are detected by our olfactory system.

The Dual Routes of Scent

Airborne odor molecules reach the nasal cavity via two distinct pathways, each playing a different role in our eating experience.

Orthonasal Olfaction: This is what we typically think of as smelling. Odors enter the nostrils from the external environment as we inhale. This pathway alerts us to food's presence and quality before we even begin to eat, such as the inviting aroma of baking bread.
Retronasal Olfaction: As we chew and swallow, volatile molecules from the food move from the mouth up through the nasopharynx to the nasal cavity. This retronasal route is crucial for creating the complex flavor profile we associate with specific foods. It's why food tastes bland when you have a stuffy nose and this pathway is blocked.

The Neuroscientific Link Between Smell and Appetite

The brain's processing of olfactory information is directly and powerfully linked to appetite regulation, cravings, and our motivation to eat. This connection is why a whiff of a favorite food can trigger intense hunger even if we are not physically hungry.

Neurological and Physiological Effects:

Limbic System Activation: The olfactory bulb sends signals to the limbic system, a brain region involved in emotion and memory. This explains why food aromas can trigger powerful, emotionally charged memories and cravings, like being reminded of childhood cookies.
Hypothalamus Signaling: The olfactory system also connects to the hypothalamus, a key area for regulating hunger and satiety. This brain region may respond to food aromas by triggering hunger signals, which can be particularly challenging for individuals trying to manage their weight.
Cephalic Phase Responses: Just smelling food can trigger a "cephalic phase response," a preparatory physiological process that prepares the body for digestion. This includes increased salivation, gastric acid secretion, and the release of insulin, priming the body for the anticipated meal.

Comparison of Olfactory Pathways


Feature	Orthonasal Olfaction	Retronasal Olfaction
Source	External environment (inhaled air)	Mouth and throat (chewing/swallowing)
Function	Detects food in the environment; scouting	Detects complex flavor of food being eaten
Associated Behavior	Anticipatory, searching for food	Consumption, appreciating texture/flavor
Percept	Broad, often a learned cue for potential food	Specific, combined with taste for full flavor profile
Neural Processing	Processed primarily in the piriform cortex	Integrated with taste information in the orbitofrontal cortex

The Impact of Olfactory Cues on Eating Behavior

Olfactory cues, consciously or subconsciously, guide our food choices and consumption habits. For example, studies have shown that brief exposure to an indulgent food smell, like a cookie, can increase a craving, while prolonged exposure might actually decrease it. Ambient smells in a supermarket can subtly influence purchases, with bakery aromas encouraging the sale of fresh bread.

The Consequences of Lost Smell

Losing the sense of smell, a condition known as anosmia, has a drastic impact on eating. Because 80% of what we perceive as taste is actually smell, people with anosmia find most foods bland and unappetizing. This can lead to nutritional problems, unhealthy weight loss, or in some cases, unhealthy weight gain from compensating with excess salt and sugar.

Effects of Anosmia on Eating:

Foods taste bland, limited to only basic tastes.
Appetite is often reduced due to the lack of enjoyment in eating.
Safety is compromised as the inability to smell spoilage increases the risk of food poisoning.
Malnutrition can occur if the loss of appetite becomes severe.
The social pleasure of sharing meals is diminished, which can affect mental health.

Conclusion

The connection between smell, appetite, and taste is a complex dance orchestrated by our nervous system. Our olfactory system not only allows us to enjoy the rich, nuanced flavors of food but also triggers deep-seated physiological and psychological responses that drive our desire to eat. Understanding how does smell play a role in appetite and taste can help us become more mindful eaters, address disorders of smell and taste, and even use aroma to guide healthier eating habits. This intricate sensory integration proves that to fully appreciate our food, we must first engage our powerful and often underappreciated sense of smell.

**** The importance of the olfactory system in human well-being: a cross-sectional review

Frequently Asked Questions

When you have a cold, nasal congestion blocks the retronasal olfactory pathway, preventing odor molecules from reaching the receptors in your nasal cavity. Since smell accounts for about 80% of what we perceive as flavor, food seems bland and tasteless because you can only detect the five basic tastes.

Yes, smelling an appetizing food can trigger a neurological response that makes you feel hungry. The aroma activates reward centers in the brain and signals the hypothalamus, which regulates hunger, potentially leading to eating even when you are full.

Taste refers to the five basic sensory perceptions detected by the tongue: sweet, sour, salty, bitter, and umami. Flavor is the total sensory experience, combining these basic tastes with the much more nuanced input from your sense of smell and other senses like texture and temperature.

The brain's olfactory bulb is directly connected to the limbic system, the region responsible for emotion and memory. This unique wiring allows aromas to trigger vivid, emotionally-charged memories more quickly and powerfully than other senses.

Yes, losing your sense of smell can pose safety risks. Without the ability to detect important warning scents like smoke from a fire, natural gas leaks, or the odor of spoiled food, you are more vulnerable to hazardous situations.

Individuals with anosmia, or the complete loss of smell, often report a significant decrease in the pleasure of eating, finding food unappealing. This can lead to eating too little and potentially malnutrition, or overeating by adding excessive salt and sugar to compensate for the blandness.

Yes, smell training can help improve olfactory function. This involves regularly and mindfully sniffing a variety of different scents in a controlled environment to stimulate and reorganize the olfactory system. For individuals with a diminished sense of smell, this can help them relearn specific odors.