What to eat and drink before and after a flu shot: Expert Q&A

What should you eat and drink before and after a flu shot? We asked three experts for tips and advice. Image credit: Tatiana Maksimova/Getty Images

Staying up-to-date with yearly flu shots is an important step in maintaining day-to-day health.
However, some people may be worried about some of the more common side effects, like mild fever, or about feeling faint while getting the vaccine.
Medical News Today spoke to experts about what foods and drinks might help mitigate or prevent any short-term side effects from getting a flu shot.

All international and national health organizations, including the Centers for Disease Control and Prevention (CDC)Trusted Source, agree that it is important to get vaccinated against the flu on a yearly basis, typically in the autumn and winter season, to prevent not just getting ill due to infection with the influenza virus, but also potential serious complications that may arise from getting the flu.

Flu shots are both safe and effective, but some people may still worry about potential side effects. The most common side effects are mild and do not last very long, and they can include low grade fever, headache, muscle aches, and nausea.

These side effects are expected, and they are often a sign that the vaccine is working — it is teaching the body’s immune system to fight the influenza virus, which can result in these mild and temporary inflammatory responses.

Other people might worry about feeling faint during vaccination — this can be due to anxiety around needles or about vaccines.

So what can you do to prevent or mitigate these reactions during and after a flu shot? What you eat and drink before getting the vaccine could help your body go through this experience more smoothly.

To get some expert tips on how to keep our flu shot experiences positive with the help of healthy dietary choices, Medical News Today spoke to Michelle Routhenstein, MS, RD, CDCES, CDN, a preventive cardiology dietitian at EntirelyNourished, and to Elena Rolt, MSc, DipION, IFMCP, rCNHC, nutritional therapist at Health.Miro, and Şebnem Ünlüişler, MSc, genetic engineer and Chief Longevity Officer at the London Regenerative Institute in the United Kingdom.

What should you eat and drink before a flu vaccine?

For those worried about becoming dizzy and feeling faint during or immediately after a flu shot, Routhenstein recommended hydrating well and eating light, whole foods.

“To help prevent dizziness or lightheadedness, stay well-hydrated and eat a light, balanced snack before a flu shot,” she advised.

The dietitian explained that:

“Drinking water or herbal tea supports circulation and maintains blood volume, which helps prevent fainting and keeps energy levels stable. A snack containing protein and complex carbohydrates, such as a banana with nut butter, stabilizes blood sugar, providing steady energy and reducing the risk of feeling weak or lightheaded during and after the shot.”

“As a genetic engineer, I often look at how nutrition can support our immune system at a cellular level, particularly around vaccination. While food and drink cannot change the efficacy of the flu jab itself, certain choices may help the body respond more smoothly and ease common side effects,” Ünlüişler clarified.

She also emphasized the importance of stabilizing blood sugar levels before getting vaccinated, “particularly for those who may feel lightheaded or anxious about needles.”

Like Routhenstein, Ünlüişler recommended a protein- and complex carb-rich snack pre-flu jab, suggesting yogurt with oats or wholegrain toast.

She also cautioned that “even mild dehydration can increase feelings of dizziness,” recommending drinking “water or an electrolyte-rich drink [as] a simple preventive measure.”