Keto DietKeto Flu

Let's Talk About the Keto Flu

If you're trying the keto diet for the first time, you might be surprised by some of the initial side effects. We asked the experts what to watch out for.

    Our Pro PanelKeto Flu

    We went to some of the nation's top experts in the keto diet to bring you the most up-to-date information possible.

    William S. Yancy, Jr., M.D.

    William S. Yancy, Jr., M.D.Director; Associate Professor of Medicine

    Duke University Diet and Fitness Center; Duke University School of Medicine
    Durham, NC
    Elisabetta Politi, R.D.

    Elisabetta Politi, R.D.Nutrition Director

    Duke University Diet and Fitness Center
    Durham, NC
    Lisa Sasson, R.D.

    Lisa Sasson, R.D.Associate Dean for Global Affairs and Experiential Learning; Clinical Professor of Nutrition and Food Studies

    New York University
    New York, NY

    Frequently Asked QuestionsKeto Flu

    What’s the most common symptom of the keto diet?

    Constipation! It can be hard to keep things moving with such limited amounts of carbs. Adding keto-friendly fibrous produce to your meals, like cauliflower, chard, and berries, can help.

    How serious is the keto flu?

    As far as medical risks go, not very. In fact, it’s not really a flu at all: You won’t have a fever and it’s not caused by an infection. But you may feel sluggish and have GI issues.

    Does the keto flu cause insomnia?

    As first, it might. Your body uses carbs to produce a hormone known as melatonin, which sends “feeling sleepy” signals to your brain. Without enough carbs to kickstart melatonin production, you may have trouble falling asleep.

    Why do I feel tired on keto?

    A diet low in carbs makes it hard for your body to hold onto water, and therefore electrolytes. That can result in dehydration (which makes you tired) or an electrolyte imbalance, which can affect blood pressure and muscle strength.

    Tula Karras

    Tula Karras

    Tula Karras is an award-winning journalist, editor, and content creator who specializes in health, nutrition, and profile writing.