Dietary changes can lead to rapid fluctuations in your body weight, and some people notice the scale going up after starting keto.
Gaining weight on keto is often the result of water retention, not body fat gain. If you’re retaining water, it usually signals an imbalance in your diet or lifestyle that requires adjustment.
Let’s explore the potential causes of weight gain and water retention on keto and learn natural ways to help reduce fluid retention while following a low-carb diet.
What is water weight?
Water weight, also known as fluid retention, refers to excess fluid that accumulates in your body’s tissues, organs, and cellular spaces. Unlike stored body fat, which develops gradually through dietary and lifestyle habits, water weight can fluctuate dramatically within hours or days.
Several factors, including nutrient balance, hormonal changes, dietary influences, medications, and lifestyle habits, can influence water retention.
Maintaining a healthy lifestyle that emphasizes proper hydration, nutrient-rich food, physical activity, and stress reduction is key to supporting optimal fluid balance.
Watch the video below to learn common causes of water retention while on keto.
Causes of fluid retention on keto
When following low-carb diets such as the ketogenic diet, your body undergoes metabolic shifts that directly impact how water is retained and eliminated.
During ketosis, carbohydrate intake is drastically reduced. This depletes glycogen, the body’s stored form of glucose, which is tightly bound to water. Approximately three grams of water are bound to every gram of glycogen.
In the early stages of keto, glycogen stores are depleted, and the associated water is released, which is why many people experience rapid initial weight loss.
However, water weight can return just as quickly under certain conditions.
“You’re typically not gaining fat when the scale goes up on keto; it’s usually just fluid accumulation. The key is understanding what’s triggering the retention,” explains Dr. Berg.
Here are three of the most common causes of fluid retention on keto.
1. Electrolyte imbalance
Electrolyte balance, especially the ratio of sodium and potassium, is often overlooked when starting a keto diet.
Sodium and potassium regulate fluid balance at the cellular level, with sodium pulling water into tissues and potassium helping to flush excess fluid.
Most people eat high amounts of sodium but not enough potassium-rich foods, such as leafy green vegetables, avocados, and salmon, to help maintain equilibrium.
Ideally, the body should maintain a 4:1 ratio of potassium to sodium. Without enough potassium to counterbalance sodium, your kidneys retain water instead of releasing it, leading to water retention and bloating.
2. Excessive fiber intake
Beneficial gut bacteria play a crucial role in digestive functions as they help break down fiber.
However, if you aren’t used to eating many vegetables, your gut microbiome may struggle to process a sudden increase in fiber-containing foods, especially when starting a nutritious Healthy Keto® diet.
Since soluble and insoluble fiber absorb water in the digestive tract, an abrupt increase in fiber without adequate microbial breakdown can lead to bloating, constipation, and water retention.
3. Hidden carbohydrates
Even small amounts of hidden carbohydrates in processed foods, even those labeled low-carb or keto-friendly, can affect water retention.
Many packaged foods contain hidden ingredients such as maltodextrin, dextrose, or modified starches that can spike blood sugars and insulin.
This disrupts ketosis and triggers glycogenesis, which causes water retention to bind glycogen reserves in muscles and the liver, leading to water weight gain.
Furthermore, frequent insulin spikes can deplete vitamin B1, an essential nutrient for fluid balance and carbohydrate metabolism.
5 ways to lose water weight on keto
If you’re dealing with fluid retention after starting keto, there are several ways that you can help your body restore a healthy fluid balance without disrupting your progress.
Here are five natural strategies to lose water weight on keto.
1. Support digestion and ease into fiber intake
Increasing your intake of non-starchy vegetables too quickly can overwhelm digestion, causing fluid retention, bloating, and constipation.
To help your body adapt to digesting larger quantities of fiber, start with small amounts of cooked vegetables and gradually add raw, fibrous greens as your digestive system adjusts.
Incorporating probiotic-rich, keto-friendly foods, such as raw sauerkraut or other fermented foods can enhance microbial diversity and B vitamin absorption, which supports fluid balance and helps avoid unexpected weight gain from water retention.
2. Incorporate natural diuretics
Certain herbs and foods naturally help the body release excess fluid.
Dandelion greens are rich in potassium and support liver function and water release. According to research published in Medicinal Herbs in Primary Care, “Dandelion leaf has diuretic, choleretic, and anti-inflammatory properties.”1
Garlic, black tea, and parsley are additional herbal options that can promote diuresis, meaning they help increase urine production to reduce excess water retention in the body.
Unlike synthetic diuretics, which may deplete minerals, these foods can support fluid release while maintaining nutrient balance.
For example, black tea can help eliminate sodium without significantly affecting potassium levels, supporting a healthier fluid balance in those with high sodium levels.
3. Avoid processed foods
Eating processed foods is the most common factor that prevents weight loss success.
These foods have little to no nutritional value and often contain hidden ingredients that contribute excess calories from low-quality sources that lead to spikes in insulin, increased appetite, and poor nutrient balance.
To help prevent water retention, it’s crucial to avoid processed foods and carefully read labels to identify hidden carbs and harmful ingredients.
4. Follow Healthy Keto
Following a Healthy Keto eating plan, which emphasizes high-quality, nutritious whole foods is one of the best things you can do to promote fluid balance.
Healthy Keto food staples, such as leafy green vegetables, full-fat dairy products, grass-fed beef, and unfortified nutritional yeast, are rich sources of potassium and vitamin B1.
This nutritious meal plan also supports blood sugar control, reduces cravings, and helps suppress appetite naturally, which can contribute to better weight management and less water retention.
5. Practice intermittent fasting and dry fasting
Intermittent fasting enhances the natural diuretic effects of ketosis by maintaining low insulin levels.
Additionally, dry fasting, which involves abstaining from food and water for a short period, usually between 10 and 18 hours, can help remove excess water, promote fat burning, and reduce puffiness from water retention.
However, this strategy should only be attempted once you’re fat-adapted and consistently in ketosis. Begin with water fasting, and avoid intense physical activity or heat exposure during dry fasts.
Ensure your electrolytes are balanced before beginning any fast to help minimize unnecessary stress or dehydration.
Other causes of weight gain on keto
Not limiting carb intake enough, consuming too many calories, or incorporating too much fat can quickly exceed the body’s energy requirements and lead to difficulty losing weight.
Even healthy high-fat foods, such as olive oil, fat bombs, and nut butter, should be consumed in moderation to promote the burning of stored body fat rather than relying solely on dietary fat for energy.
Additionally, poor lifestyle habits such as a sedentary lifestyle, persistent snacking, or consuming too much alcohol can impair fat burning and promote fluid retention, and negatively impact overall body composition.
To support fat loss on keto and help prevent weight gain, focus on healthy fats, tracking your daily net carbs, building muscle mass, and creating an efficient routine that promotes healthy weight loss.
Other factors that can cause weight gain on keto include hormonal changes, such as elevated cortisol from chronic stress or poor sleep, which may trigger sudden weight gain and make it more difficult to burn body fat efficiently.
Additionally, medical conditions such as polycystic ovarian syndrome, heart failure, kidney and liver disease, or thyroid problems can contribute to hormonal imbalances that may increase fluid retention despite carefully monitoring carb and fat intake.
If you suspect an underlying medical condition may be contributing to weight gain, it’s important to consult with a qualified healthcare provider to determine the most appropriate approach for your individual health needs.
Key takeaways
It’s not uncommon to experience weight fluctuations when starting a low-carb diet, and gaining weight on keto is often due to water retention, not fat gain.
Several factors can contribute to water retention-related weight gain, including nutrient imbalances, inflammation, digestive issues, or shifts in glycogen storage due to cheat days or hidden carbs.
Adjusting your fiber intake, utilizing natural diuretics, avoiding processed foods, following Healthy Keto, and practicing fasting can help your body adapt to burning fat, prevent hunger, and discourage water retention.
FAQ
1. Why am I gaining weight on the keto diet?
Initial weight gain on keto is often temporary water retention linked to electrolyte imbalances, increased fiber intake, low vitamin B1 levels, or hidden carbohydrates disrupting ketosis.
However, if you’re not tracking your macronutrients, you might be consuming too many carbs, which can block fat burning and promote fat storage.
2. What causes water weight gain on keto?
Water retention during ketosis can result from low vitamin B levels, potassium-sodium imbalances, inefficient fiber digestion, or hidden carbs, all of which can stimulate water retention.
3. Is it normal to gain water weight when you start keto?
Yes, it’s common for people to gain water weight when first starting keto. Generally these weight fluctuations signal a need for dietary and lifestyle adjustments in order to support the metabolic changes required to achieve ketosis and become fat-adapted.
4. How do I stop water retention on keto?
To manage water retention while pursuing a Healthy Keto® lifestyle, balance your intake of electrolytes, particularly potassium and sodium, and gradually increase low-carb vegetables to help your body adjust.
Additionally, boost your vitamin B1 levels with keto-friendly options, such as unfortified nutritional yeast, avoid processed foods, and limit carbohydrate intake to maintain stable ketosis.
5. Do I need to count calories to lose weight on keto?
No, counting calories isn’t always necessary on keto. A nutrient-dense, low-carb, high-fat diet can help regulate appetite naturally, making it easier to consume fewer calories without strict tracking.
