Ice water hack for weight loss: does it work?

There’s no shortage of wellness “hacks” online, and one you may have come across is the ice water hack for weight loss. With so many trends circulating online, it’s hard to know which are legit. 

So, is the ice water weight loss hack too cool to be true? Does it actually work, or is it another case of internet hype? Here’s what you need to know. 

The ice water hack refers to using ice-cold water to stimulate calorie burning and, in turn, weight loss. This could involve drinking ice water throughout the day or engaging in more extreme cold exposure through cold plunges or ice baths. 

The scientific principle behind the ice water hack is cold-induced thermogenesis. Your body is meant to maintain a temperature of around 98.6°F, and very cold temperatures can throw this off.

“When you introduce something very cold, like ice water, into your system, your body must expend energy to heat it up and maintain that stable temperature,” says Dr. Hans J Schmidt, MD, Chief of Bariatric Surgery at Hackensack University Medical Center. And yes, this energy expenditure is measured in calories.

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Although the ice water hack can help you burn some more calories, it doesn’t necessarily help you lose weight.

“The idea that drinking ice water can be a 'hack’ for weight loss is technically true but highly exaggerated in practice,” Dr. Schmidt says. “While your body does burn calories to warm the cold water up to your core body temperature, the number of calories burned is very small.”

He says that drinking a 16-ounce glass of ice-cold water can burn around 8 calories, which means if you drink 8 glasses of ice water a day, it can help you burn an extra 64 calories. “While this is not zero, it is a very minor amount in the context of a daily diet, equivalent to about half an apple or a few minutes of walking,” Dr. Schmidt says.

To top that off, we also do not have any studies that suggest that drinking ice water can lead to significant weight loss.

Yes, drinking ice water is safe for the vast majority of healthy people, Dr. Schmidt says.

“The primary risk is not from the temperature of the water itself, but from drinking an excessive amount of water of any temperature too quickly,” says Dr. Schmidt. “This can lead to a dangerous condition called water intoxication or hyponatremia, where the body's sodium levels become dangerously diluted.” 

When your sodium levels are too low, it can cause your cells to swell, particularly brain cells, which can lead to a range of symptoms such as headache, nausea, and vomiting, or in more serious cases, seizures or coma.

However, this happens when you drink a lot of water at once, like if you’re chugging several cups of water one after another. If you’re drinking water at a normal rate, you do not run the risk of hyponatremia from too much water consumption, no matter what temperature the water may be. Additionally, from the ice-cold temperature, you may experience a minor, temporary side effect: brain freeze. Dr. Schmidt explains this is a brief headache caused by the cold affecting nerves in the roof of the mouth. It’s not dangerous, just uncomfortable, and it generally passes quickly.

Lastly, in people with certain pre-existing conditions, like achalasia (a swallowing disorder) or those who are prone to migraines, Dr. Schmidt says very cold liquids can sometimes trigger symptoms.

Yes, again, drinking ice water throughout the day is generally safe for most healthy individuals. The main concern is the risk of hyponatremia. However, if you’re a healthy person, you would have to drink around 18 liters of water (iced or not) throughout the day to experience hyponatremia.

To give you an idea of how excessive that is, the general guidelines for water intake are 3.4 liters per day for men and 2.6 liters per day for women. However, exact guidelines depend on your weight and activity level. 

For many healthy individuals, cold plunging may be safe; however, it comes with risks. One risk is hypothermia, when your core body temperature gets dangerously low. Another risk is cardiac stress, Dr. Schmidt says. Intense, sudden cold exposure, or “cold shock,” causes an increase in heart rate and blood pressure. This can pose a bigger problem for those with underlying heart conditions. You also run the risk of drowning if you experience any adverse effects while you’re in the water, especially if you’re alone.

Check with your healthcare provider to get clearance before trying a cold plunge. Not to mention, cold plunging shouldn't be your main weight loss tool. “It is not a practical or sustainable primary weight loss strategy for most people due to the extreme discomfort and potential health risks,” Dr. Schmidt says. “It is better viewed as a supplementary practice for potential metabolic benefits rather than a replacement for foundational health habits.”

The ice water hack recipe is super simple: just pour yourself a glass of ice water. To enhance the taste, you can add an optional squeeze of fresh lemon or lime. 

For a potentially more positive impact, try drinking a glass of water before your meals. Some research suggests that drinking water before your meals can promote feelings of fullness (AKA satiety), which can help you eat less, and in turn, consume fewer calories.

If you want a little electrolyte boost, you can add a pinch of pink Himalayan salt, too.  

If you’re trying to lose weight, it’s better to use science-backed methods rather than relying on any type of “hack,” Dr. Schmidt says.

Here are five more legitimate alternatives:

• Maintain a calorie deficit: “Consistently maintaining a modest calorie deficit is the cornerstone of weight loss, which means consuming slightly fewer calories than your body burns through a balanced diet rich in whole foods,” Dr. Schmidt says.

• Eat a diet rich in protein and fiber: Prioritizing protein and fiber in your diet can significantly aid in weight loss by increasing satiety (feelings of fullness) and reducing your overall caloric intake, Dr. Schmidt says. 

• Exercise more: Getting regular exercise is key for weight loss. Dr. Schmidt recommends a combination of both strength training and cardiovascular exercise. “Strength training builds muscle, which increases your resting metabolism, while cardio directly burns calories,” he says.

• Get enough high-quality sleep: Sleep is an often-overlooked aspect of a weight loss plan. “Poor sleep disrupts the hormones that regulate hunger and appetite, often leading to increased cravings and weight gain,” Dr. Schmidt says. 

• Consider weight loss medications: In some instances, your healthcare provider may suggest weight loss medications, such as glucagon-like peptide-1 (GLP-1) receptor agonists, if you’re struggling to lose weight through the above methods. Examples of these include Wegovy (semaglutide) and Zepbound (tirzepatide). These meds help you regulate your appetite and promote a calorie deficit, but it’s best to use them as a part of a comprehensive treatment plan that includes lifestyle changes. 

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The premise of the ice water hack for weight loss is based on real science, but the effect is so small that it’s unlikely to make a noticeable difference in your weight. Ultimately, the ice water hack is ineffective for meaningful weight loss. 

• Cold temperatures do increase the amount of calories you burn, but only very slightly, which is unlikely to have a major impact on your daily calorie intake, and thus, weight loss. 

• Drinking ice water is safe for the vast majority of healthy people, as long as you aren’t consuming an excessive amount.

• Cold plunges do result in some calorie burn, but they also come along with health risks for some populations.

• Opt for more legitimate, science-backed weight loss methods, such as maintaining a calorie deficit, adopting a healthy lifestyle, or considering weight loss medications if recommended by your healthcare provider.