Recovering From A COVID-19 Infection: What Role Do Nutrition And Diet Play In Your Post-Coronavirus Climb To Better Health?

It's been 10 months since the COVID-19 pandemic started, and over 35 million people have contracted the disease during that period, myself included.

COVID-19 might be different from other viruses in a number of ways, but what's the same with most infections is that people lose their appetites, and, consequentially, also strength and weight.

I had a mild form of the disease; I didn't need to be hospitalized, experienced only a mild fever, a few days of diarrhea, trouble breathing for a couple of days, and that's it. I still lost 11 kilos (more than 24 pounds). When I returned to work, it took me weeks to recover my pre-COVID productivity levels, and my boss even allowed me to take 30 minute naps when ever I felt like it, setting up a resting place at work. And I needed those naps a lot.

Ordinary tasks left me physically exhausted, and even my 20-minute walk to work (there was no way I was getting on a bus again) made me feel so tired that I needed to rest for 15 minutes when I got to my lab. All of this is, in a sense, very normal and expected. On one hand, your body is tired from fighting the infection. On the other hand, you don't eat as much as you used to when you were healthy, so you have less fuel to draw energy from.

Why do we lose appetite when we're sick?

Whenever we catch an infection, the body's immune system activates several defense mechanisms. This includes many different types of cells, each of which play a different role, tens of different chemicals produced both by those cells, and other cells as well, and even gene expression moderation, depending on the cause of infection.

Now, as fascinating as this story is (to me, at least), it's way too complicated to be explained in just one text (if you're actually interested in understanding how our immune system works, I recommend Basic Immunology: Functions and Disorders of the Immune System by Abul K. Abbas et al.).

As noted previously, many cells produce numerous different chemicals, and the roles of those chemicals (called cytokines) are are also varied. Some activate certain white blood cells, some help them move to a specific location, and some help the white blood cells stay alive, while others promote cell suicide. Aside from white blood cells, cytokines affect other cells as well. And, if we're talking about loss of appetite, the cells influenced by cytokines are in the part of the brain called the hypothalamus. This part of the brain regulates feeding.

Now, why would there be any evolutionary benefit to losing appetite while you're fighting an infection? It seems quite illogical to limit the intake of nutrients when nutrients are most needed, and more energy is lost both to fighting an infection, and due to faster metabolism caused by fever. 

There are many hypotheses to possibly answer this question, but most scholars agree that the reason we lose appetite when we're ill is actually energy preservation; animals will not spend time and energy looking for food if they're not hungry. Staying in one place also helps preserve heat. It should additionally be noted that bacteria use some minerals, such as zinc and iron, to grow and reproduce. If you limit the intake of those elements, you limit their growth as well.

What should I eat after COVID infection?

Basically, you need protein and calories. Calories to regain the weight that you lost and to boost your energy, and proteins to help rebuild the muscles that atrophied while being ill. The right diet will boost your immune system as well.

Here are some nutritional tips which you might find helpful, whether you're recovering from COVID-19 yourself or know someone who recently had the coronavirus:

• First of all, your diet should be rich in protein. Each meal you eat should ideally contain 25 grams of protein, and your daily intake of protein should be somewhere between 75 and 100 grams. Or you can calculate it yourself: protein requirements for a person who is not underweight or overweight is 1.2 to 2.0 g/kg of actual body weight. Fish and chicken are rich in protein. Vegetarian-friendly options for protein rich meals include eggs, milk and dairy products, legumes, peanuts, pulses and soy (be careful with soy, though, because in contains phytoestrogens).
• It is important to stay hydrated, and the recommended intake of water is 1.5 liters, plus any losses. You don't have to get all this from simple glasses of water; you can make soups and broths as well (avoid alcoholic beverages, because they actually make you lose water).
• Sensory loss is one of the common symptoms seen in COVID-19 patients, and not being able to taste or smell the food you're about to eat certainly doesn't help bring back your appetite. Don't be afraid to use spices and herbs to make your meal more appealing. Drink carbonated soft drinks. Add dry fruit to your meals. Use chopped nuts as toppings. Basic tastes are still present, so you can emphasize those to make your meal tastier. Warm food is less bland and more appealing than cold food (such as sandwiches).
• Nausea is also a common symptom in COVID patients. If you're experiencing it, it is recommended to have many smaller meals during the day. A person with this condition should eat smaller meals every two hours. If nausea is present, strong smells should be avoided, as well as hot food — opt for sandwiches instead.
• Be sure that your meals are rich in calories. Consider adding potatoes, pasta, bread, grains, and rice to your meals. 

Be patient. Even in very mild cases where patients don't suffer from the now increasingly notorious "long COVID-19", which features prolonged symptoms even after the infection clears, recovery takes a few weeks, A healthy diet can help you recover faster. Plus, you might change some of your bad habits along the way.