Does Cold or Hot Water Increase Metabolism? Unpacking the Myths

October 6, 2025 •

3 min read

According to a study published in The Journal of Clinical Endocrinology & Metabolism, drinking cold water increased metabolic rate by up to 30% for over an hour, a fact often exaggerated. This metabolic boost, known as thermogenesis, is minimal and is not a shortcut to significant weight loss, yet the question of whether cold or hot water increases metabolism remains a topic of widespread interest.

Quick Summary

Cold water requires the body to expend energy to warm it, causing a minimal and brief thermogenic boost, while warm water primarily aids digestion. The minimal calorie burn from water temperature is not a significant factor in weight loss; consistent hydration, diet, and exercise are far more impactful. The best strategy is to drink water at a temperature you prefer to ensure consistent hydration.

Key Points

Cold water burns negligible calories: While your body does expend energy (thermogenesis) to warm cold water to body temperature, the amount of calories burned is minimal and not a significant factor for weight loss.
Warm water supports digestion: Instead of directly boosting metabolism, warm water aids digestion, promotes satiety, and can help you feel fuller, which indirectly helps with weight management.
Hydration is the key: Consistent hydration, regardless of water temperature, is the most critical factor for supporting a healthy metabolic rate. Dehydration can slow your metabolism.
Choose based on comfort: The best water temperature is the one that encourages you to drink enough of it. Personal preference is more important than chasing a minimal, unproven metabolic edge.
Timing matters for different goals: Drink cold water during workouts for thermoregulation, and consider warm water before meals for better appetite control and digestion.

The Science of Water, Temperature, and Metabolism

The human body is designed to maintain a stable core temperature. When you drink water that is colder or warmer than your internal temperature, your body uses energy to bring it to a neutral state, a process called thermogenesis. However, the amount of energy expended in this process is quite small.

The Minimal Impact of Cold Water Thermogenesis

While the body does burn a few extra calories warming cold water, the effect is not significant for weight loss. Studies suggest that drinking a glass of ice water might burn only about 8 extra calories. This is a negligible amount in the context of overall daily caloric intake and expenditure. Relying on cold water drinking for substantial weight loss is not an effective strategy.

The Role of Warm Water in Digestion and Satiety

Warm water doesn't trigger the same thermogenic response as cold water but offers benefits for digestion and appetite. Many traditional health practices recommend warm water for its soothing effect on the digestive system. Drinking warm water before meals may aid digestion, stimulate digestive enzymes, and contribute to feelings of fullness, potentially helping to manage calorie intake. These indirect effects can support weight management efforts, but warm water isn't a direct metabolic enhancer like some believe cold water to be.

The Overlooked Factor: Consistent Hydration

Far more important than water temperature is maintaining consistent hydration. Dehydration can hinder metabolic rate and efficiency, while adequate water intake supports metabolic processes and nutrient utilization. Studies show that drinking water, regardless of temperature, can temporarily increase metabolic rate. Staying hydrated also helps the body distinguish between thirst and hunger, potentially reducing unnecessary eating.

How to Strategically Use Water Temperature

Morning Kickstart: Starting the day with warm water is favored by some for its perceived digestive benefits.
Workout Performance: Cold water is often preferred during and after exercise to help regulate body temperature and improve performance and recovery.
Before Meals: Drinking water, particularly warm water, about 30 minutes before eating can help promote fullness and control portion sizes.
Throughout the Day: Prioritize drinking water at a temperature you find enjoyable to ensure consistent hydration, which is the most impactful factor for metabolism.
Digestive Support: Warm water can be a gentler option for individuals experiencing bloating or slow digestion.

Water Temperature and Metabolism: A Comparison


Feature	Cold Water	Warm Water
Thermogenic Effect	Minimal. Your body expends a small number of calories to warm the water to core temperature.	Minimal. The body doesn't need to expend energy to heat the water.
Calorie Burn	An estimated 8-12 extra calories per 500ml.	No additional calories burned via thermogenesis.
Appetite Control	Can briefly blunt appetite, especially when consumed before a meal.	Often used before meals to feel full longer, promoting appetite control.
Digestion	May slightly slow down digestion in some individuals by constricting blood vessels.	Supports faster gastric emptying and digestive enzyme activity.
Workout Benefits	Excellent for cooling the body during and after intense exercise, improving performance.	Not as effective for thermoregulation during physical activity.
Overall Impact	Minimal metabolic effect, but indirect support through hydration and potential workout enhancement.	Minimal metabolic effect, but indirect support through appetite control and better digestion.

Conclusion

While cold water does lead to a tiny increase in calorie expenditure due to thermogenesis, this effect is too small to contribute significantly to weight loss. The idea that water temperature dramatically increases metabolism is a misconception. The most effective approach for supporting your metabolism through hydration is to ensure you drink enough water consistently throughout the day. Combining proper hydration with a balanced diet and regular exercise will have a far greater impact on your metabolism and overall health than the temperature of your water. Choose the water temperature that encourages you to drink more. For additional insights, a resource from Stanford University also supports this conclusion.

Frequently Asked Questions

No, drinking cold water causes a minimal and temporary increase in metabolism as your body expends a small amount of energy to warm it. The effect is too slight to be a significant weight-loss strategy.

Warm water does not have the same thermogenic effect as cold water. However, it can aid digestion and increase feelings of fullness before meals, which indirectly supports weight management. Neither temperature offers a magic bullet for significantly boosting metabolism.

Scientific estimates suggest that drinking one glass (approximately 250ml) of ice-cold water burns only about 8 extra calories as your body heats it to core temperature. This is a very small number.

No, you cannot lose significant weight simply by drinking cold water. The caloric effect is negligible and must be combined with a balanced diet, regular exercise, and consistent hydration for any meaningful results.

Adding lemon to water, whether hot or cold, can enhance flavor and help regulate blood sugar levels, but it doesn't dramatically boost metabolism on its own. It's a supportive habit, not a primary fat-burning mechanism.

Drinking a glass of water, especially warm water, about 30 minutes before a meal can help reduce calorie intake by promoting feelings of fullness. This can be a helpful strategy for weight management.

Yes, absolutely. Ensuring you are consistently and adequately hydrated is far more important for maintaining a healthy metabolic rate and overall bodily function than the temperature of your water.