How much water do you need per day?
Personalised advice in litres and glasses, based on your weight, activity level and climate. Staying well hydrated supports weight loss and is especially important when using GLP-1 medication.
- Base
- 35 ml
- per kg
- Exercise
- +500
- ml / 30 min
- Heat
- +500
- ml extra
Water helps more than you think
Water is one of the most underrated tools for weight loss. Zero calories, it fills your stomach and helps your body break down fat. A German study found that people who drank 500 ml of water before each meal lost 44% more weight than the control group.
Want faster results? Swap soft drinks, fruit juice and sweetened coffee for water. A glass of cola (330 ml) already contains 35 grams of sugar. Over a week, that saves you thousands of calories without giving anything up.
A dull or pressure-like feeling, especially in the afternoon.
Light yellow is ideal. Dark means: drink more.
Even 2% dehydration noticeably lowers your energy.
Thirst is often mistaken for hunger. Drink first.
Hydration advice with GLP-1 medication
Medications like Wegovy, Ozempic or Mounjaro slow down your stomach emptying. This means dehydration can cause symptoms more quickly: headaches, nausea and constipation.
- →Drink 2 to 3 litres spread throughout the day.
- →A glass of water before each meal.
- →If you feel nauseous: small sips throughout the day.
- →Lemon or mint for flavour without sugar.
General information
about GLP-1 medication.
Below you'll find an overview of the best-known GLP-1 medications. This is general, informational content. Which medication, dosage or treatment is right for you is always determined by a doctor during a personal intake, alongside lifestyle guidance.
Semaglutide at a higher dose, specifically registered for weight management in adults with overweight or obesity.
- Active ingredient
- Semaglutide, a GLP-1 receptor agonist at a higher dose.
- Usage
- Once a week via a subcutaneous injection using a specially designed pen.
- Target group
- For people with obesity (BMI ≥30) or overweight (BMI ≥27) with weight-related conditions.
- How it works
- Mimics the natural GLP-1 hormone, reduces appetite, slows gastric emptying and improves satiety.
- Potential weight loss
- An average of 16.9% in clinical research after 68 weeks, at the highest dose.
- Side effects
- Mainly nausea, gastrointestinal complaints and fatigue. These usually decrease over time.
This medication is available on prescription only and should be used under professional medical supervision. A personal screening and regular check-ins are essential for safe and effective treatment. This medication is not covered by health insurance.
Everything you want to know
about drinking water.
- How much water should I drink per day?
- For the average adult, that's 30 to 40 ml per kg of body weight. For 70 kg, that's about 2.5 litres. Exercise, heat and pregnancy all increase that need.
- Does drinking water help with weight loss?
- Yes. Drinking water before a meal helps you feel fuller and lowers your calorie intake. It also replaces sugary drinks that are full of empty calories.
- How many glasses is 2 litres?
- With an average glass of 250 ml, that's 8 glasses. If you use larger 330 ml glasses, you'll need 6.
- Can you drink too much?
- In healthy people, rarely. More than 4 litres in a single day can disrupt the sodium levels in your blood. Spread your intake throughout the day and listen to your body.
- Does coffee count?
- Yes, up to about 4 cups a day. Moderate caffeine intake does contribute to your fluid intake. Water and tea remain the best choice.
- Should I only drink when I'm thirsty?
- No. By the time you feel thirsty, you're already mildly dehydrated. Drink throughout the day, even when you don't feel thirsty.
- How much water with GLP-1 medication?
- At least 2 litres a day, ideally 2.5 to 3 litres. Staying well hydrated helps prevent issues like headaches, nausea and constipation.
- Water before or during a meal?
- A glass of water 15 minutes before your meal works best for satiety. During the meal is fine too, though some experts suggest it can slow digestion.
Blog about medical weight loss
Read our articles about medical weight loss, lifestyle, nutrition, medication, obesity, exercise and healthy living.
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