Do You Lose Your Appetite With COVID? Here’s Why

Appetite loss is one of the most common symptoms of COVID-19, reported by a majority of hospitalized patients and a significant share of people with milder infections. In one study of over 300 patients, roughly 58 percent had lost their appetite by the time they were admitted to the hospital. The reasons go well beyond simply “feeling too sick to eat.” COVID-19 attacks appetite through several distinct pathways at once, from hijacking your sense of taste and smell to triggering inflammation in the gut and disrupting the hormones that tell your brain you are hungry.

How Common Appetite Loss Actually Is

Appetite loss during COVID-19 is not a minor or rare complaint. A study of 301 patients found that 58 percent had anorexia on admission, and the rate climbed even higher among those with severe disease compared to mild or moderate cases.¹ Among hospitalized patients in the Netherlands, decreased appetite ranked as one of the most predominant nutrition-related complaints, alongside shortness of breath and altered taste.² Even people with relatively mild COVID at home frequently report that food simply does not appeal to them for days or weeks. The symptom tends to be underappreciated compared to cough or fever, but it has real consequences for recovery, particularly in older adults and people who were already nutritionally vulnerable before they got sick.

Your Immune System Is Doing This on Purpose

The drop in hunger you feel during COVID is not a random side effect of being ill. It is a deeply conserved biological response found across virtually all animals, from insects to mammals. Researchers call it sickness-associated anorexia, and it appears to serve a real function during infection. When your body detects a pathogen, inflammatory signals dial down your appetite intentionally.³

Why would your body want you to stop eating in the middle of a fight for survival? The evidence points to several potential benefits. Reducing food intake during infection lowers circulating amino acids, which ramps up a cellular recycling process called autophagy. That recycling helps immune cells clear pathogens and damaged material more efficiently. A 2024 review in Metabolism described sickness-associated anorexia as an evolutionary strategy to increase tolerance to illness, noting that fasting during infection triggers the release of ketone bodies and other mediators that suppress inflammation, help cells adapt to using fat for fuel, and resist the kind of cellular stress that pathogens cause.⁴ In other words, the miserable feeling of not wanting to eat when you are sick may actually be your immune system optimizing its own performance.

This does not mean you should deliberately starve yourself through COVID. The evolutionary advantage of short-term appetite loss during an acute infection is a population-level phenomenon, not personalized medical advice. When appetite loss becomes prolonged or severe, it starts working against you by depleting muscle and energy reserves you need for recovery.

When Food Tastes Wrong or Smells Revolting

One of the most distinctive features of COVID-19 is its attack on the senses of taste and smell, and this plays a direct role in appetite suppression. Early in the pandemic, complete loss of smell and taste became a hallmark symptom. But the appetite impact does not end when those senses start to return. Many patients develop parosmia, a distortion of smell where familiar, previously pleasant odors become unbearable. Common triggers include coffee, onions, garlic, fried or roasted meats, eggs, and bell peppers. For some people, the reaction is intense enough to cause gagging or vomiting. In extreme cases, patients cannot eat at all and require tube feeding to maintain adequate nutrition.⁵

Research on the relationship between these sensory changes and eating behavior consistently points in one direction. A review in Nutrients noted that altered smell and taste perception mainly induces reduced appetite, leading to a faster feeling of fullness during meals and, as a result, weight loss.⁶ This makes intuitive sense. The smell and taste of food are not just pleasant bonuses; they are fundamental drivers of appetite. When your brain no longer receives the sensory reward it expects from eating, hunger signals weaken. People stop wanting to cook because the process itself is unpleasant. They gravitate toward bland, cold foods that produce minimal odor. The overall pattern is a significant reduction in caloric intake that can persist for weeks or months after the acute infection resolves.

The Gut Gets Hit Directly

COVID-19 is not purely a respiratory disease. SARS-CoV-2 uses the ACE2 receptor to enter cells, and that receptor is densely expressed on the cells lining the upper gastrointestinal tract. The virus infects the gut’s enterocytes directly, triggering inflammation, cell death, and the release of signaling molecules that drive nausea and vomiting through both local and brain-mediated pathways.⁷ Nausea is, obviously, a powerful appetite suppressant. But the GI damage goes beyond just making you feel queasy.

When the virus interacts with ACE2, it can also raise levels of a hormone called angiotensin II in the blood. Angiotensin II acts on a part of the brain involved in triggering the vomit reflex, providing yet another mechanism through which the virus suppresses your desire to eat.⁷ So even if your GI symptoms seem mild, the virus may be quietly disrupting the signaling between your gut and your brain in ways that make food unappealing.

In patients who develop longer-lasting gut problems after infection, the microbiome also shifts. Research on post-COVID gut dysbiosis has documented a decrease in beneficial bacteria that produce short-chain fatty acids and an increase in opportunistic species. This shift contributes to a leakier gut barrier, which allows bacterial products to enter the bloodstream and sustain low-grade inflammation, further disrupting the gut-brain communication that regulates hunger and satiety.

Hunger Hormones Get Disrupted

Your appetite is regulated in part by hormones, and COVID-19 appears to scramble at least one of them. Ghrelin, sometimes called the “hunger hormone” because it signals your brain that it is time to eat, was found at significantly higher levels in COVID-19 patients compared to healthy controls in a study published in the Journal of Clinical Medicine.⁸ That might sound counterintuitive, since higher ghrelin should mean more hunger, not less. But the relationship between circulating ghrelin and actual appetite is not always straightforward.

During acute illness and systemic inflammation, the brain can become less responsive to ghrelin’s “go eat” signal, a phenomenon researchers have seen in other inflammatory conditions. The same study found that sex influenced the relationship between COVID-19 and ghrelin, with male patients showing lower ghrelin levels than female patients.⁸ Interestingly, leptin, the “satiety hormone” that generally signals fullness, did not differ significantly between COVID patients and controls. The hormonal disruption seems to be more about a breakdown in the hunger signal’s effectiveness than a straightforward increase in fullness signaling.

Variant Matters

Not every COVID-19 infection suppresses appetite equally. As the virus mutated into new variants, the symptom profile shifted. A large study comparing Omicron and Delta infections in England found that loss of appetite was less common during Omicron infections than during Delta infections.⁹ The difference was statistically meaningful, though both variants could still cause it. This tracks with the broader pattern researchers noticed: Omicron tended to cause more upper-respiratory symptoms and fewer systemic complaints compared to Delta.

If you caught COVID recently and did not lose your appetite, the variant you were infected with may be one reason why. But population-level immunity from prior infection and vaccination also blunts the severity of most symptoms, appetite loss included. The point is that appetite loss is not a universal feature of every COVID-19 infection anymore, even though it remains a common one.

Paxlovid Can Make Things Worse

Here is an irony that many COVID patients have encountered firsthand: the antiviral treatment itself can suppress your appetite. Paxlovid, the oral antiviral that became widely prescribed for people at higher risk of severe illness, carries a well-documented side effect of dysgeusia, a distortion or metallic taste that makes food deeply unappealing. An analysis of FDA adverse event reports found that dysgeusia was associated with about 16 percent of Paxlovid reports.¹⁰ A separate pharmacovigilance study put the figure at roughly 17.5 percent and found that Paxlovid was far more likely to cause taste disturbance compared to other antiviral treatments.¹¹

Patients often describe the Paxlovid taste as an intense, persistent bitterness or metallic flavor that coats the mouth and does not go away with brushing or mouthwash. This stacks on top of whatever taste disruption the virus itself already caused. For someone who was barely managing to eat because food tasted off, adding Paxlovid-induced dysgeusia can tip the scales toward skipping meals entirely. The taste disturbance from the drug typically resolves within a few days of finishing the course, but during those five days of treatment, eating can feel genuinely punishing. Women appear to report this side effect more frequently than men.¹¹

What Prolonged Appetite Loss Does to Your Body

A few days of eating less while you ride out a fever is generally not dangerous for an otherwise healthy person. But COVID-19 has a habit of stretching appetite loss across weeks, and the consequences can be serious. Among hospitalized patients, one study found that one in five suffered serious acute weight loss, and nearly three-quarters were at high risk for sarcopenia, the rapid loss of muscle mass and strength.² Almost all patients had at least one nutrition-related complaint.

The combination of appetite loss, taste and smell changes, and the body’s inflammatory response creates a double hit: you eat less while your body burns through energy and protein at an accelerated rate. Researchers have described this as a collision of decreased food intake and heightened catabolism, the breakdown of muscle tissue for energy.¹² Older adults are especially vulnerable because they often enter the illness with lower muscle reserves and may already be eating less than they need. But younger patients who spent prolonged time in bed, particularly in ICUs, are not immune to these effects either.¹³

The muscle loss from COVID is not just cosmetic. It translates directly into physical weakness, difficulty with daily activities, and slower overall recovery. Someone who loses significant muscle mass during a two-week bout with COVID may need months to rebuild it, and that process requires adequate protein intake, which is hard to achieve when your appetite has not fully returned.

Practical Strategies for Eating When Nothing Sounds Good

If you are in the middle of COVID and struggling to eat, a few practical approaches can help you get through the worst of it without your nutritional status cratering:

Eat cold or room-temperature food: Heating food intensifies its aroma, which is a problem if smells are triggering nausea or disgust. Cold sandwiches, yogurt, smoothies, and chilled soups tend to be more tolerable.
Prioritize calorie density: If you can only manage a few bites, make them count. Nut butters, cheese, avocado, and protein shakes deliver more energy per mouthful than salads or broth.
Eat small amounts frequently: Three large meals are often overwhelming. Six small snacks spread across the day may be more manageable, especially if early fullness is a problem.
Stay hydrated separately: Drinking large amounts of fluid with meals can increase fullness. Sip fluids between meals instead, focusing on water, electrolyte drinks, or diluted juice.
Manage Paxlovid taste: If the metallic taste from Paxlovid is the main barrier, strong flavors like citrus, ginger, or mint can partially mask it. Some patients find that sucking on hard candy between doses helps.

These are not cures. They are damage-control measures to maintain some level of intake while your body fights the infection and your appetite gradually recovers. If you find yourself unable to eat or drink anything for more than a couple of days, or if you are losing weight rapidly, that warrants a conversation with your doctor, particularly if you are older or have an underlying condition.

When Appetite Loss Drags On After Recovery

For most people, appetite returns within a week or two of symptom onset, roughly tracking with the resolution of fever and fatigue. But a subset of patients report persistent appetite suppression that lasts for months as part of the broader long COVID picture. The mechanisms at play in these prolonged cases likely overlap with but are not identical to those during acute infection. Ongoing gut dysbiosis, lingering inflammation, and persistent parosmia can all keep appetite suppressed long after the virus itself has been cleared.

Parosmia in particular can be a stubbornly long-lasting problem. Some patients report distorted smell persisting for six months to a year, gradually improving as olfactory neurons regenerate. During that window, the list of tolerable foods may shrink dramatically, and the psychological burden of dreading every meal takes its own toll on nutritional status. If appetite loss persists well beyond the acute illness, it is worth flagging for a healthcare provider, as targeted interventions like smell retraining therapy and nutritional counseling can help bridge the gap while the body heals.

1
Nutrition Clinique et Métabolisme. Evaluation of anorexia and analysis of related factors in patients with COVID-19
2
PubMed Central. Poor nutritional status, risk of sarcopenia and nutrition related complaints are prevalent in COVID-19 patients during and after hospital admission
3
PubMed Central. Sickness-Associated Anorexia: Mother Nature’s Idea of Immunonutrition?
4
PubMed. Starvation and infection: The role of sickness-associated anorexia in metabolic adaptation during acute infection
5
PubMed Central. Parosmia and altered taste in patients recovering from Covid 19
6
PubMed Central. Eating Habits and Body Weight Changes Induced by Variation in Smell and Taste in Patients with Previous SARS-CoV-2 Infection
7
PubMed Central. COVID-19, nausea, and vomiting
8
PubMed Central. Ghrelin and Leptin Concentrations in Patients after SARS-CoV2 Infection
9
PubMed Central. Comparative symptomatology of infection with SARS-CoV-2 variants Omicron (B.1.1.529) and Delta (B.1.617.2) from routine contact tracing data in England
10
PubMed. Adverse Events Associated with Antivirals for COVID-19: An Analysis Based on FDA Adverse Event Reporting System (FAERS)
11
PubMed. Postmarketing Reporting of Paxlovid-Related Dysgeusia: A Real-World Pharmacovigilance Study
12
PubMed Central. Post-COVID-19 acute sarcopenia: physiopathology and management
13
PubMed Central. Malnutrition and Sarcopenia in COVID-19 Survivors