What Counts as Water When Dieting for Proper Hydration?

November 20, 2025 •

4 min read

According to the British Dietetic Association, all non-alcoholic drinks, including tea, coffee, and milk, count toward your total fluid intake, debunking the myth that only plain water contributes to hydration. Understanding what truly counts as water when dieting is crucial for weight loss, as adequate fluid intake can help manage appetite and boost metabolism.

Quick Summary

This article explores the wide range of beverages and foods that count toward your daily fluid intake during a diet, distinguishing calorie-free options from those with added sugars. It covers the hydrating properties of coffee, herbal teas, and milk, along with water-rich fruits and vegetables, offering practical advice for meeting your hydration targets effectively.

Key Points

Variety of fluids: Your total fluid intake comes from all beverages, including plain water, tea, coffee, and milk, not just plain water.
Caffeine is not dehydrating in moderation: The fluid in a moderate amount of coffee or tea outweighs the mild diuretic effect of caffeine.
Food provides hydration: About 20% of daily fluid intake is sourced from foods, especially high-water fruits and vegetables like cucumber and watermelon.
Calorie-dense drinks can hinder dieting: Sugary sodas, full-fat milk, and high-sugar juices contain extra calories that can prevent weight loss.
Pre-meal water can suppress appetite: Drinking water before meals can help you feel fuller, leading to reduced calorie consumption.

Hydration Beyond the Glass: What Really Counts?

When you're trying to lose weight, staying hydrated is a key component for managing hunger and maintaining energy levels. While plain water is the gold standard for zero-calorie hydration, it is not the only source of fluid you consume daily. A significant portion of your fluid intake comes from other beverages and even the food you eat. This broader view of hydration can help you meet your goals without getting bored of plain water.

Beverages that Contribute to Your Fluid Intake

Many dieters believe that caffeinated beverages like coffee and tea are dehydrating, but this is a persistent myth. While caffeine has a mild diuretic effect, the fluid content of these drinks is far greater, meaning they still contribute positively to your hydration status.

Coffee and Tea: Both caffeinated and decaffeinated varieties count. For weight loss, it's best to enjoy them without added sugars or high-calorie creamers. Brewed coffee is roughly 99% water.
Herbal Tea: Naturally caffeine-free herbal teas like peppermint, chamomile, and ginger are excellent calorie-free ways to increase fluid intake and add variety.
Milk and Plant-Based Milks: Milk is approximately 90% water and provides essential nutrients like calcium and protein. Adults and older children on a diet should opt for lower-fat versions to manage calories.
Broth and Soups: Broth-based soups can be an excellent way to get hydrating fluids while also providing warmth and satiety.
Fruit and Vegetable Juices: While they provide fluid, 100% fruit juices contain calories and natural sugars. It is recommended to limit intake to one small glass (150ml) per day to minimize calorie and sugar consumption. Diluting them with water or sparkling water is another strategy to reduce sugar intake.

Water-Rich Foods for Optimal Hydration

About 20% of your daily fluid intake comes directly from the foods you eat. Incorporating water-rich fruits and vegetables can significantly help you reach your hydration targets while also boosting fiber and nutrient intake.

Melons: Watermelon and cantaloupe have extremely high water content.
Berries: Strawberries are among the most hydrating fruits.
Leafy Greens: Lettuce and spinach contain high amounts of water.
Crisp Vegetables: Cucumber, celery, and bell peppers are almost entirely water.
Cooked Dishes: Soups, stews, and oatmeal are also great sources of fluid.

Drinks to Limit or Avoid While Dieting

To keep your diet on track, it's important to differentiate hydrating drinks from those that provide empty calories or can hinder your progress. Drinks with high levels of added sugar, caffeine, or alcohol should be limited or avoided. Sugary drinks can increase your calorie intake without providing essential nutrients, and alcohol can be dehydrating.

Beverage Comparison for Dieters


Beverage Category	Hydration Contribution	Calorie Content	Diet Considerations
Plain Water	Very High	Zero	Best choice; calorie-free and essential for all bodily functions.
Black/Green Tea (Unsweetened)	High	Minimal	Mild diuretic effect offset by fluid; great for flavor. Limit with added sugar.
Herbal Tea	High	Zero	Excellent calorie-free alternative to plain water.
Coffee (Black, Moderate)	High	Minimal	Mild diuretic effect manageable at moderate intake. Avoid high-calorie add-ins.
Milk (Low-fat)	High	Moderate	Good source of nutrients, but contributes calories.
100% Fruit Juice	Moderate	Moderate-High	Contains vitamins but also sugar and calories. Best limited to 150ml daily.
Sugar-Sweetened Soda	Minimal	High	High in sugar and calories; linked to weight gain. Should be avoided.
Alcohol	Minimal	High	Diuretic effect promotes fluid loss. Can hinder weight loss. Should be limited.

Practical Tips for Hydration on a Diet

Making a conscious effort to stay hydrated can significantly impact your dieting success. Here are some actionable tips to incorporate more fluids throughout your day.

Carry a Reusable Water Bottle: Keep a water bottle with you at all times to encourage frequent sipping.
Infuse Your Water: Add slices of lemon, cucumber, or mint to plain water for a burst of flavor without extra calories.
Start Your Day with Water: Drink a glass of water first thing in the morning to kick-start your hydration.
Drink Before Meals: Consuming water before meals can help you feel full, potentially leading to reduced calorie intake.
Listen to Your Body: While thirst is an indicator, don't wait for it. Keep an eye on the color of your urine, which should be pale yellow, as a reliable hydration marker.
Include High-Water Foods: Prioritize fruits and vegetables with high water content in your meals and snacks.
Consider Electrolytes for Intense Exercise: If you engage in high-intensity, prolonged exercise, sports drinks can help replenish electrolytes, but for moderate activity, plain water is sufficient. For example, the RACGP recommends pre-meal water consumption, noting the practice's evidence-based benefits.

Conclusion

While the simple advice to 'drink more water' holds true, the reality of what counts towards your hydration when dieting is much broader. Understanding that a variety of beverages and even food can contribute to your fluid intake is key. From calorie-free herbal teas and modest amounts of coffee to water-rich fruits and vegetables, you have many options to keep your body properly hydrated. For dieters, the most important distinction is between calorie-free hydrating options and calorie-dense drinks that can sabotage weight loss efforts. By focusing on smart, healthy fluid choices, you can better manage appetite, support metabolic function, and ultimately, achieve your dieting goals.

Frequently Asked Questions

Yes, contrary to popular myth, both tea and coffee contribute to your daily fluid intake. While caffeine is a mild diuretic, the hydrating effect from the liquid is significant enough to count, especially with moderate consumption.

Yes, soups and broths are great sources of fluid and count towards your total daily intake, in addition to being a low-calorie, hydrating food option.

Diet sodas, being mostly water, do contribute to hydration. However, many contain artificial sweeteners and can perpetuate a preference for sweet flavors. Calorie-free options like water, herbal tea, or flavored sparkling water are healthier alternatives.

Many fruits and vegetables, such as watermelon, strawberries, cucumber, and lettuce, have a high water content and can provide a significant portion of your daily fluid needs. Eating these foods also adds fiber and vitamins.

Daily water needs vary based on age, weight, and activity level. A common guideline is to drink half your body weight in ounces per day, but listening to your body and checking your urine color are reliable indicators of hydration.

To add flavor to water, try infusing it with natural ingredients like fresh mint, lemon, lime, or berries. This provides variety without introducing extra sugar or calories.

While your body does burn a few extra calories to warm cold water to body temperature (thermogenesis), the effect is minimal and not a significant factor in weight loss. It is a myth that cold water can have a large impact on calorie expenditure.