We’ve all heard it before: drink more water. Many populations don't meet the minimum water intake recommendations, but how much water do you actually need if you're trying to lose weight? Is it eight glasses a day? A gallon? Should you carry one of those giant motivational jugs around everywhere?
The short answer is, it depends, but yes, drinking more water can help with weight loss. Water can naturally suppress your appetite and increase your metabolism slightly, especially if you're replacing high-calorie drinks with it.
You will be shocked to find out what happens to your body when you stop reaching for soda and grab a mineral water instead. That sweet burn is still as satisfying, and you will cut your calorie intake drastically.
Why water helps
A 2016 study published in Frontiers in Nutrition found that water may increase metabolism by boosting mitochondrial function (your cells' energy factories). This leads to increased fat burning (lipolysis) in fat cells.
There have been small short-term studies that found that drinking a full glass of water before meals made people eat less.
One theory? It helps you feel fuller and faster. People following a low-calorie diet who drank extra water before meals had less appetite and more weight loss over 12 weeks than those on a similar diet without the extra water, per Harvard Health.
Another plus: Dehydration can sometimes feel like hunger, leading to mindless snacking when your body really just needs H2O. When you're dehydrated, you can feel sluggish. Hydration = more energy to go to the gym, and better digestion, which always helps with weight loss.
How much should you try to drink?
How much water you need to stay hydrated really depends on your body size and how active you are. A common baseline is around 2.7 liters (about 11 cups) per day for women and 3.7 liters (about 15 cups) for men, according to the U.S. National Academies of Sciences. But that includes fluids from food, too. You can also aim to drink half your body weight in ounces.
If you're sweating it out at the gym, you'll want to increase your water intake to help your body recover fast.
Of course, more isn’t always better. There is such a thing as drinking too much water, and it can throw off your electrolyte balance and lead to hyponatremia. So don't force it, listen to your body, and sip throughout the day instead of chugging a gallon in one go.
Pro tip: Keep a reusable water bottle within reach. If you're someone who "doesn't like water, " then flavor it naturally with lemon, cucumber, or mint. Every little sip adds up. If you love sparkling water, get a machine to make it at home.
Bottom line? Water alone won’t make the weight fall off, but it's a low-effort, high-reward habit that supports digestion, energy, and overall health.