Losing weight can be a challenging process for many people. With so much misinformation online, it can be difficult to know what tips really work. One popular weight loss claim is that drinking warm water can boost your metabolism and help you slim down. But is this fact or fiction?
In this article, we’ll explore the evidence behind drinking warm water for weight loss. We’ll look at the potential benefits, downsides, and overall effectiveness of adding warm water to your daily routine if you’re trying to shed pounds.
What is the claim behind warm water and weight loss?
The idea that drinking warm water can help with weight loss stems from the belief that it can boost your metabolism. Specifically, some claim that by drinking warm water, you can raise your core body temperature. This is said to increase the rate at which you burn calories both during and after drinking the water.
Proponents also argue that warm water can maximize the rate at which the water passes through your body. Faster water throughput is claimed to reduce water retention and “flush” more calories from your system. Some even say warm water can suppress appetite by filling up your stomach.
Is there any research to support these claims?
There is limited scientific research directly examining the impact of warm water on weight loss. However, some related studies provide insight into the potential mechanisms.
One small study looked at the impact of drinking 500mL of water at different temperatures in 21 healthy volunteers. They measured the change in resting energy expenditure (REE), which calculates the number of calories burned at rest. The results showed that drinking cold water increased REE by up to 30% for 60-90 minutes, while warm water consumption had no significant effect on REE.[1]
So while cold water did appear to give metabolism a slight boost in this study, warm water did not. However, more research is still needed looking specifically at warm water and metabolism over a longer period.
In terms of water throughput, one study found that both cold and hot water emptied from the stomach faster than lukewarm or room temperature water.[2] This suggests that extremes of temperature can speed up gastric emptying. So there may be some validity to the claim that warm water passes through the body more quickly than cooler water.
When it comes to appetite suppression, one study found feelings of fullness were higher after drinking water chilled to 3°C compared to 37°C. However, more research is needed comparing warm versus cooler water.[3]
Overall, current research provides limited and mixed evidence for the proposed mechanisms behind warm water aiding weight loss. More robust clinical studies are still needed.
What are the potential benefits of drinking warm water?
Despite the lack of strong evidence, there are some potential benefits to drinking warm water if you’re trying to lose weight:
May give your metabolism a small boost
While the boost may be minor, some research suggests drinking any temperature of water can briefly increase the number of calories burned at rest. So warm water may still provide a slight metabolism lift.
Can help you stay hydrated
Drinking an adequate amount of water is important for weight loss. Warm water may help you meet your fluid needs and stay hydrated, keeping your body functioning properly.
May reduce water retention
Some individuals find warm fluids less bloating than cooler fluids. This may be because warm liquids can promote vasodilation (expansion of blood vessels), which improves circulation and helps flush out excess water.
Can be soothing
The warmth itself can be soothing for many people, making warm water a pleasant beverage to frequently consume throughout the day.
What are the potential downsides?
There aren’t many drawbacks to drinking warm water, but a few potential cons include:
May not suppress appetite as well as cold water
Some research indicates cold water may be more effective for appetite suppression. So if you’re drinking warm water in hopes it will fill you up, you may be disappointed.
Not providing optimal hydration for workouts
Cold water is usually recommended for rehydrating during and after exercise. The cool temperature allows the body to absorb the fluid more rapidly.
Possibility of scalding
Drinking water that is too hot could burn your mouth. Aim for warm but not dangerously hot temperatures.
Does the temperature of the water impact absorption?
In general, the impact of water temperature on absorption in the body is considered minor. Once water reaches your stomach, any differences in temperature tend to equalize quickly.
However, some research has found colder water emptying from the stomach slightly faster than warm water. Here is a summary of absorption rates:
| Water Temperature | Gastric Emptying Rate |
|---|---|
| Cold (3°C/37°F) | Faster emptying from the stomach |
| Room temperature (21°C/70°F) | Moderate emptying rate |
| Warm (37°C/98.6°F) | Slower emptying than cold water |
| Hot (Above 43°C/109°F) | Rapid emptying from the stomach |
So while very cold and hot liquids may have a slight advantage, the differences in absorption time are unlikely to be major.
Does the timing of drinking warm water matter?
The time of day you drink warm water likely does not have a significant impact. However, first thing in the morning may provide some advantages:
Can boost hydration after sleep
Sipping warm water when you wake up can help replenish fluids lost during sleep. Starting your day well-hydrated gives you an edge.
May support digestion
For some, warm water first thing promotes regularity and improves digestion. The movement of warm liquid through your stomach and intestines can get things flowing.
Potential to enhance weight loss
If warm water does give your metabolism a slight lift, drinking it in the morning may maximize the effect by boosting calorie burn early in the day.
How much warm water should you drink?
There are no guidelines specifically for warm water intake. The standard recommendation is to drink at least eight 8-ounce glasses of fluid daily. You can count warm water toward your total fluid intake.
A good rule of thumb is to sip warm water frequently throughout the day. Drinking it steadily keeps you hydrated and allows you to consume an adequate amount.
Should you drink warm water before or after meals?
Here is a summary of the potential benefits of drinking warm water before or after meals:
| Timing | Benefits |
|---|---|
| Before meals |
|
| After meals |
|
Drinking warm water either before or after meals appears to offer some advantages. Pay attention to when you feel the effects most strongly.
Should you drink warm water before bed for weight loss?
Drinking warm water before bed may provide several benefits related to weight loss:
Enhances hydration at night
Sipping some warm water before bed helps you go to sleep optimally hydrated. This may reduce water retention.
Could boost overnight metabolism
If warm water does elevate metabolism even slightly, having some before bed may continue boosting calorie burn while you sleep.
May promote bowel regularity
The movement of warm water through your digestive system can stimulate peristalsis. This may support morning regularity.
However, avoid drinking large amounts close to bedtime, as this may disrupt sleep with frequent urination.
What are the best practices for drinking warm water?
Here are some tips for optimizing your warm water intake:
Gradually increase your water temperature
Start with room temperature water and slowly work your way up to warmer temperatures as tolerated.
Aim for about 130-140°F/55-60°C
This range provides pleasant warmth without scalding your mouth.
Try adding lemon
For flavor and added benefits, try squeezing some fresh lemon juice into your warm water.
Drink it steadily throughout the day
Sipping warm water at regular intervals optimizes hydration and any potential metabolic effects.
Listen to your body
Note when you feel the greatest benefits from warm water and adjust your timing accordingly.
The bottom line
Research has yet to conclusively demonstrate that drinking warm water can help you lose weight. But there are some modest benefits possible, mainly related to keeping you hydrated, potentially boosting metabolism slightly, and promoting feelings of fullness.
Given that there are no risks to regularly drinking warm water, it’s reasonable to test it out for yourself. Pay attention to your individual experience. If you feel it benefits your weight loss efforts, keep at it. But stick with plain water only, not warm beverages with added sugar and calories.
When combined with a solid diet and exercise regimen, warm water may provide that extra edge for successful weight loss. But it should not be viewed as a magic bullet on its own.
References
[1] https://www.ncbi.nlm.nih.gov/pubmed/14671205
[2] https://www.ncbi.nlm.nih.gov/pubmed/18589027
[3] https://www.ncbi.nlm.nih.gov/pubmed/23390511
