When you start a new diet or exercise regimen, you may notice a rapid drop in weight after just a few days. But don’t get too excited, because most of that “fast weight loss” is not fat, but water.
So, what is water weight, why does it fluctuate, and what does it mean for your weight loss journey?
What is water weight?
Water weight (also known as water weight) is the excess fluid that the body retains in its tissues, joints, and blood vessels.
The human body is already about 60% water, so it’s completely natural for weight to fluctuate due to changes in water content.
This change can cause you to gain or lose several hundred grams, or even several kilograms, in just a few days. This leads many people to mistakenly believe that they are “gaining” or “losing” weight quickly. But in reality, it’s just water, not fat.
How is water weight different from fat loss?
This is important. Because:
- Water weight loss is temporary, and can happen in just a few hours or days.
- Real fat loss requires time, consistency, and a sustained calorie deficit. This means you have to consume fewer calories than your body burns.
Many people, after starting a diet, see a loss of 2–3 kg in just the first week and think they have “burned fat” very well. In fact, most of this change is due to the body losing water and glycogen, not a significant amount of fat.
When you return to a normal diet or consume more salt and starch, this water can increase very quickly, causing the weight to increase, even though the amount of fat has not changed.
Why Does the Body Retain Water?
Water retention (water retention) is a completely natural reaction of the body. However, there are a number of factors that can make this condition more pronounced, especially if you are watching your weight closely. Here are some common causes:
1. Eating too much salt (sodium)
The sodium in salt has the ability to retain water in your cells. When you eat salty foods (like canned foods, fast food, sauces or processed foods), your body will retain water to dilute the excess sodium.
As a result, you may feel bloated, puffy or heavier, and your weight may temporarily increase by 1–2 kg after just one high-salt meal.
2. Eating too much carbohydrate
Carbohydrate is the body’s main source of energy and is stored as glycogen in the liver and muscles. Each gram of glycogen stored will retain 3–4 grams of water. So, when you eat a lot of starch (like rice, noodles, bread), your body will retain more water.
Conversely, when you cut carbs, your glycogen stores decrease, which in turn reduces your body’s water content. This is why you lose weight quickly in the first few days of a low-carb diet, but it’s water, not fat.
3. Hormonal changes
In women, fluctuations in estrogen and progesterone during the menstrual cycle can cause temporary water retention, especially in the abdomen, hips, and legs.
This explains why many people feel “heavier” or “bloated” in the days before their period, even if their diet hasn’t changed.
4. Dehydration (drinking too little water)
The paradox is that when you don’t drink enough water, your body retains more water. When you’re dehydrated, your body activates its “self-protection” mechanism, holding onto the remaining water in your tissues to avoid further dehydration.
Therefore, drinking enough water every day not only helps to detoxify your body, but also reduces water retention.
5. Lack of exercise, sitting in one place for long time
Sitting or standing for long periods without moving can cause fluid to accumulate in the legs and feet due to the effects of gravity. If you work in an office or fly for long hours, you may notice swelling in your ankles or feet, which is a sign of temporary fluid retention.
Why understanding water weight is important for weight loss?
Understanding water weight can help you stay mentally stable during weight loss. If you see a 1–2 kg increase on the scale overnight, don’t panic. It’s not fat, it’s just a temporary change in the amount of water in your body.
Similarly, if you lose weight very quickly in the first few days, don’t think you’ve “burned fat fast.” Most of that weight will come back as your body restores normal water and glycogen levels.
Instead of obsessing over the number on the scale every day, track the overall trend over several weeks or months. That’s the only way to know if you’re actually losing fat.
How to lose water weight naturally?
Although water weight is temporary, there are healthy ways to reduce water weight and make your body feel lighter and more comfortable:
1. Reduce salt (sodium) intake in your diet
Limit processed foods, soy sauce, canned foods, instant noodles or fast food. Choose natural spices like lemon, garlic, pepper or herbs for flavor instead of using a lot of salt.
2. Drink enough water every day
Drinking plenty of water actually helps the body eliminate excess sodium and helps the kidneys function better. A well-hydrated body will not need to “retain” water anymore, thereby reducing the feeling of bloating and swelling.
3. Exercise regularly
When you exercise and sweat, your body releases excess water, while improving blood circulation. Even a light 30-minute walk every day will help reduce water retention.
4. Eat potassium-rich foods
Potassium helps balance sodium in the body, thereby reducing water retention.
Foods rich in potassium include: bananas, sweet potatoes, spinach, avocados and oranges.
5. Cut back on refined carbohydrates
Cutting down on white bread, pasta, crackers or soft drinks can help reduce the amount of glycogen and water stored in the body.
Instead, choose whole grains and fresh fruits and vegetables – they provide more sustained energy.
In short, water weight is just a natural fluctuation in the body’s process of maintaining balance. Once you understand this mechanism, you will no longer be discouraged by small daily fluctuations in your weight. Instead, focus on sustainable habits such as eating a healthy diet, exercising regularly and getting enough sleep. Weight loss is really about improving your health over time, not just a number on the scale.
