Why do I feel shaky if I don't eat carbs? The truth about low-carb withdrawals

October 25, 2025 •

4 min read

According to the CDC, shakiness is a common symptom of low blood sugar, which is a major reason why many people ask, why do I feel shaky if I don't eat carbs?. This uncomfortable phenomenon is a direct result of your body's intricate energy system adjusting to a sudden change in its primary fuel source.

Quick Summary

When carbohydrate intake drops, the body transitions from burning glucose to fat for energy, triggering a stress response. This metabolic shift can cause temporary hypoglycemia, electrolyte imbalances, and hormonal fluctuations that manifest as physical shakiness.

Key Points

Hypoglycemia is a primary cause: Shakiness is often a symptom of low blood sugar (hypoglycemia), which can occur when you suddenly stop eating carbohydrates.
The 'Keto Flu' is a common factor: The body's transition into ketosis, where it burns fat for energy instead of glucose, can trigger flu-like symptoms including shakiness, fatigue, and headaches.
Electrolyte imbalance plays a role: Reducing carbs leads to water and electrolyte loss (sodium and potassium), which can cause dehydration and shaky feelings.
Hormonal response is triggered: When blood sugar drops, the body releases stress hormones like epinephrine, causing tremors, anxiety, and a rapid heart rate.
Symptom management is key: Staying hydrated, replenishing electrolytes with broth, and consuming healthy fats can help ease the transition and reduce shakiness.
It's often a temporary phase: For most people, the shaky feeling and other keto flu symptoms are temporary and subside as the body adapts to its new fuel source.
Gradual reduction can help: Easing into a low-carb diet instead of cutting carbs drastically can help minimize the shock to your system.

The Science Behind the Shake: A Metabolic Shift

Carbohydrates are your body's primary and most readily available energy source. When you eat them, your digestive system breaks them down into glucose, which enters the bloodstream to fuel your cells, muscles, and brain. When you dramatically reduce your carb intake, your body is forced to find a new fuel source. It begins to deplete its stored glucose (glycogen) and shifts to burning fat for energy, a process called ketosis. This change, while part of the goal for some diets like the ketogenic diet, can send your body into a temporary state of shock, causing several side effects that lead to that familiar shaky feeling.

Hypoglycemia: The Blood Sugar Drop

One of the most immediate and significant causes of shakiness is a drop in blood glucose levels, a condition known as hypoglycemia. In healthy individuals, the pancreas and liver work together to keep blood sugar stable. Insulin helps cells absorb glucose, while glucagon signals the liver to release stored glucose when levels get low. However, with a sudden reduction in carbs, the system can get out of balance, leading to blood sugar levels that are too low. As the brain, which relies heavily on glucose, becomes energy-starved, it triggers a 'fight-or-flight' stress response, causing the release of hormones like epinephrine (adrenaline). It's this surge of adrenaline that directly causes the nervous, shaky, or trembling sensations, along with a racing heart.

The 'Keto Flu' Connection

For many embarking on a very low-carb diet, the shaky feeling is part of a broader set of symptoms often dubbed the 'keto flu' or 'low-carb crash'. This collection of flu-like symptoms, which can also include fatigue, headaches, brain fog, and irritability, is the body's response to adapting to ketosis. It typically occurs within the first few days and can last for a week or more as the body learns to efficiently use fat and ketones for fuel. The withdrawal from carbs, particularly if your previous diet was high in refined sugars, can feel similar to withdrawing from an addictive substance.

Electrolytes and Dehydration

Another key contributor to shakiness is an imbalance of fluids and electrolytes. When your glycogen stores are depleted, your body releases large amounts of water that are bound to the glycogen. This rapid fluid loss also flushes out critical electrolytes, such as sodium and potassium. An electrolyte imbalance can lead to dehydration and directly affect nerve impulses, muscle function, and blood pressure, resulting in dizziness, fatigue, and the sensation of being shaky or weak. Many of the keto flu's symptoms are exacerbated by this electrolyte deficit, but they can often be minimized by ensuring adequate hydration and electrolyte intake.

How to Manage the Shaky Symptoms

If you're experiencing shakiness after cutting carbs, there are several steps you can take to alleviate the symptoms and support your body through the transition.

Practical Tips for Relief

Replenish Electrolytes: Drink a cup of bouillon or bone broth to increase sodium intake. Incorporate potassium-rich, low-carb foods like avocados and leafy greens into your diet.
Increase Hydration: Since carb restriction causes the body to shed water, make an extra effort to drink plenty of fluids throughout the day.
Ease into It: Rather than cutting carbs drastically overnight, try reducing them gradually. This can help minimize the shock to your system and make the transition smoother.
Eat Healthy Fats: Ensure you are consuming enough healthy fats to provide a steady fuel source as your body adapts to ketosis. This helps reduce cravings and keeps you feeling satisfied.
Get Adequate Rest: Fatigue is a common keto flu symptom. Listen to your body and give it the rest it needs. Lack of sleep can raise stress hormones, making symptoms worse.
Light Exercise: While strenuous exercise should be avoided initially, light activities like walking or yoga can help improve symptoms.

What to Eat and What to Avoid

To manage blood sugar and electrolyte balance, the types of foods you consume matter significantly.


Food Category	Description	Low-Carb Diet Approach
High-Fiber Carbs	Found in vegetables, legumes, whole grains	Gradually reduce starchy versions; prioritize fibrous vegetables like spinach and broccoli.
Refined Carbs & Sugars	Found in white bread, pasta, sugary drinks, sweets	Drastically reduce or eliminate, as these cause rapid blood sugar spikes and crashes.
Healthy Fats	Found in avocados, nuts, seeds, olive oil	Increase intake to provide a primary fuel source during ketosis.
Protein	Found in meat, fish, eggs, dairy	Maintain moderate intake to support muscle mass and aid satiety.
Electrolyte-Rich Foods	Found in bone broth, avocados, leafy greens, nuts	Actively incorporate to replace lost electrolytes and combat shakiness.

Conclusion: A Temporary Adjustment, Not a Warning

The shaky feeling that can accompany a low-carb diet is not a sign of serious illness in most cases but rather your body's natural response to a significant metabolic change. By understanding the underlying causes—hypoglycemia, keto flu, and electrolyte imbalances—you can take proactive steps to manage these uncomfortable symptoms. The transition period is temporary, and most individuals find that the shakiness subsides within a few days or weeks as their bodies become more efficient at burning fat for fuel. However, if symptoms are severe or persistent, it is always recommended to consult a healthcare professional to rule out any other underlying conditions.

For more detailed information on low-carb diets, you can visit the Mayo Clinic's guide on low-carb diets.

Frequently Asked Questions

The main reason is hypoglycemia, or low blood sugar. When you stop consuming carbohydrates, your blood glucose levels drop, and your body releases adrenaline to raise them, causing the shaky sensation.

The 'keto flu' refers to a cluster of flu-like symptoms, including shakiness, fatigue, and headache, experienced by some people when their body switches from burning glucose to burning fat for energy on a ketogenic diet.

As your body depletes its glycogen stores on a low-carb diet, it also flushes out water and key electrolytes like sodium and potassium. This imbalance can lead to dehydration and shaky feelings.

To get immediate relief, consume some fast-acting carbohydrates, like fruit juice or a small piece of fruit. To address the root cause, consider sipping on some broth to replenish sodium and stay hydrated.

Yes, for most people, the shaky feeling is temporary. It typically subsides within a few days to a few weeks as your body fully adapts to using fat and ketones as its primary fuel source.

Yes, people who are used to a high-carb diet, especially one with refined sugars, may experience more severe initial symptoms. Those who ease into the diet often have a smoother transition.

If your symptoms are severe, persistent, or accompanied by confusion, slurred speech, or loss of coordination, you should consult a doctor. It's also important to consult a healthcare professional before starting any restrictive diet, especially if you have underlying health conditions like diabetes.