You know that you need about eight glasses of water a day, but on hot summer days when you work up a sweat, your body actually thirsts for much more. Adding water-filled foods to your diet can help you stay on top of your hydration needs, and their water weight will satiate you too. In fact, you might even find you crave them on those super sweaty days. Here are five foods that have enough water to help quench your thirst and fill you up without a ton of calories. 1. Cucumber This vegetable tops the chart as the food with the highest concentration of water. Both cucumber and iceberg lettuce are 96 percent water. Enjoy cucumber in a Greek salad, with other hydrating foods, like tomatoes and peppers, or make a Chilled Yogurt Cucumber Soup. 2. Watermelon Anyone who has bitten into a piece of cold watermelon on a stifling hot summer day knows how refreshing the fruit can be. Watermelon is a super hydrating choice for a summer picnic or party. Keep it simple with fresh watermelon slices, mix it up in a Watermelon Salad, or make these Three-Ingredient Watermelon Ice Pops. 3. Radishes There’s a common misconception that hydrating foods have to be watery and flavourless, but radishes pack some powerful flavour while containing 95 percent water. Enjoy radishes on a crudités plate, add them to your favourite potato salad, or try our tasty Radish Slaw in Lettuce Cups. 4. Celery Celery has just six calories a stalk, and it’s hugely hydrating. It’s a great veggie to add to your beach picnic or post-workout snack, because it also contains sodium to help rebalance your electrolytes when you’ve been sweating. Add celery to a salad, eat it plain, or make your own celery juice. 5. Strawberries You might not expect strawberries to match watermelon in water content, but they do! While blueberries and raspberries are also hydrating, strawberries have them beat with 92 percent water content. Buy organic to get more flavourful berries, and enjoy them with a touch of balsamic, or make Strawberry Granita or a berry-full beverage. (Photography: Ryan Brook) You might also like:Hangover cures, plus a morning-after smoothie... 4 rules to healthy snacking at work or school Is there lead in your drinking water? The perfect drink for your long workout Why is everyone crazy about lemon water?