How much water to drink when you are losing fat

Almost nobody talks about water when it comes to fat loss. And it is one of the simplest things that makes the whole process easier. You do not have to force down extra litres. You just need to do a few things properly, and it helps more than you would expect.

Short answer: Roughly 30 to 35 ml per kilogram of body weight a day. For a person who weighs 80 kg, that comes to about 2.4 to 2.8 litres. If you train or it is hot outside, add more. The easiest check is the colour of your urine: light yellow is fine, dark means you need to drink.

Why water matters

Water is involved in everything in the body, from digestion to how you perform in the gym. When you are short on it, you get tired, you focus worse, and the workout is not worth much.

Then there is one thing the brain mixes up: thirst often feels like hunger. So before you reach for a snack, have a glass of water and wait a moment. Check whether it was just thirst. More on telling real hunger apart is in cravings and hunger.

How much to drink

As a rough guide, count 30 to 35 ml per kilogram of body weight a day. For a person who weighs 80 kg, that is about 2.4 to 2.8 litres. Training day or a hot day? Add more.

You do not need to measure every glass. The simplest check is the colour of your urine. Light yellow is fine. Dark means drink more.

Liquid calories: the quiet deficit killer

This is where fat loss fails most often. Sweet soft drinks, juice, sweetened coffee or alcohol put hundreds of kcal (calories) into you, and they do not fill you up at all. One glass of soda plus a small beer, and today's whole deficit is gone without you eating a thing.

If you want the numbers on drinks in particular, see alcohol and fat loss and diet soda and weight loss.

Does water really help you lose fat?

Do not expect miracles. But it helps, indirectly and reliably.

• A glass before a meal fills you up a little, so you calmly eat a bit less.
• Swap sweet drinks for water and you save calories, without giving up anything on your plate.

How big your deficit should be in the first place is in calorie deficit: how much to eat, or you can work it out with the calculator.

Practical tips

• Keep a bottle where you can see it. What you see, you drink.
• A glass of water before every meal.
• Swap sweet drinks for water or unsweetened tea.
• Watch coffee and alcohol. They count toward what you drink in a day too.

Drinking water on its own will not make anyone lose fat. But it makes the whole process a lot easier. And you will struggle to find a simpler habit that works this well.

Frequently asked questions

Does drinking water help you lose weight?

Do not expect miracles, but it helps indirectly and reliably. A glass before a meal fills you up a little, so you eat a bit less. And when you swap sweet drinks for water, you save calories.

Why are liquid calories a problem when losing fat?

Sweet soft drinks, juice, sweetened coffee or alcohol give you hundreds of calories that do not fill you up at all. A glass of soda plus a small beer can take your whole deficit for the day without you eating anything.

Can I mistake thirst for hunger?

Yes, it happens a lot. Before you reach for a snack, have a glass of water and wait a moment to see if it was just thirst.

What happens if I drink too little?

When you are short on water, you get tired, you focus worse, and your training suffers.

Sources, so you can check:

1) Guideline used in the article: about 30 to 35 ml of water per kilogram of body weight per day, more with exercise or heat; urine colour as a simple check

Martin Barna

Online nutrition and fitness coach. Since 2013 I have helped 600+ people lose fat and keep the result. Science, not crash diets.

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This article is for information only. It is not medical advice. If you have a health condition, talk to your doctor.