Does drinking cold water help to reduce weight?

Question

According to this article, it was mentioned:

there may be advantages in drinking cold water for weight loss

So, does drinking cold water really help to reduce weight? and does drinking warm water really help to increase weight?

Answer 1

TL;DR: No, not to any large extent - the effects are swamped by other, much larger factors.

• Clive M. Brown, Abdul G. Dulloo and Jean-Pierre Montani, Water-Induced Thermogenesis Reconsidered: The Effects of Osmolality and Water Temperature on Energy Expenditure after Drinking, The Journal of Clinical Endocrinology & Metabolism September 1, 2006 vol. 91 no. 9 3598-3602, doi: 10.1210/jc.2006-0407

In this study, the energy expenditure of some young subjects were measured before and after drinking 500mL of distilled water, saline, sucrose and cold (3°C) water.

Cooling the water before drinking only stimulated a small thermogenic response, well below the theoretical energy cost of warming the water to body temperature. These results cast doubt on water as a thermogenic agent for the management of obesity.

Warning: The abstract does not detail the size of the sample, except noting it was a subgroup of the main experiment.

But, we are talking about the human body, so it is more complicated than that. If you want to lose weight by increasing your energy expenditure, exercise is a major factor. If you want to exercise for long periods, ensuring you aren't dehydrated is a major factor. Which brings us to another effect of water temperature.

• Patricia C. Szlyk, Ingrid V. Sils, Ralph P. Francesconi, Roger W. Hubbard, Lawrence E. Armstrong, Effects of water temperature and flavoring on voluntary dehydration in men, Physiology & Behavior, Volume 45, Issue 3, March 1989, Pages 639–647, doi: 10.1016/0031-9384(89)90085-1

Fourteen men were offered 15°C water, 40°C water, 15°C flavored water, and 40°C flavored water while doing six hours (on-and-off) of treadmill exercise. The men were divided into two based on whether they tended to replenish the weight lost through sweat ("Drinkers" or D) or not ("Reluctant Drinkers" or RD). Both groups drank significantly more water when it was cold.

Compared to the warm water trial, 6 hr consumption of cool water was significantly increased in both D (59%) and RD (141%) and [body-weight] loss was dramatically reduced in both groups. [...] The results of this study indicate that either flavoring or cooling warm water will enhance fluid intake and reduce body weight deficits in men reluctant to drink.

Note: The short-term body-weight loss here is presumably mainly water-loss not fat-loss.

The definition of cold varies between the two studies cited. Which brings us to another interesting study.

• D. Boulze, P. Montastruc, Water intake, pleasure and water temperature in humans, Physiology & Behavior, Volume 30, Issue 1, January 1983, Pages 97–102

They offered water at a range of temperatures to some people dehydrated through sweating or mountain climbing, measured how much they drank, and asked what they preferred.

The subjects rated the coldest water as more pleasurable, but drank more when they drank it at 15°C. If given the opportunity to mix the water to a drinkable temperature, they also chose 14.9°C. This contradiction between drinking the most at 15°C but rating 0°C as more pleasurable was attributed to the volunteers being too hot as well as dehydrated:

Cold water was therefore both more pleasureable and less drunk. Dehydration resulted in a negative alliesthesia for warm water. Positive alliesthesia for cold water was probably the result of hyperthermia rather than dehydration.

Conclusions

• If you are expecting significant weight-loss due to colder water requiring more energy to heat up, you will be disappointed at the effect size.

• If you are expecting significant weight-loss due to exercise, you will rehydrate yourself better with water at 15°C - you probably don't need for a thermometer to figure that out - you will want to drink it at that temperature.

• But if you are hot, ice cold water tastes best.

Answer 2

Yes, drinking cold-water may help with weight loss, however this will probably be less effective than you'd like, and almost ineffective if used in isolation of greater diet reform and exercise.

Firstly, the Human operates at around 37.0°C (98.6°F). This is called the operating temperature. When the temperature of the body drops, the body must work harder (thermoregulate) to raise that temperature back to 98.6°F. It's just thermodynamics though. "Cold water" lowers your body temperature and because humans are warm blooded, your body will modify your metabolism to raise your body temperature: think a biological heater. This requires energy -- in dietary terms, calories:

Discovery Health and Fitness estimates this to be 70 Calories (292 kJ) a day if you drink eight 8-ounce glasses (1.9L) of 0°C ice water. Some fluids will require more energy for your body to raise to body temperature, some will require less.