Water please, cold with no ice.

Mmm... doesn’t that look good? A lot of people will probably really enjoy that cake, but at the same time, many won’t. It might be because they’re allergic to chocolate, or because they don’t like cakes, or simply because they don’t have a sweet tooth.

A 2013 study called "Temperature of served water can modulate sensory perception and acceptance of food" published in the University of Arkansas, however, suggests that the sweetness of chocolate – or rather, your perception of the sweetness can be affected by something unexpected: the temperature of the water you drink!

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In this psychological study, researchers Mony, Tokar, Pang, Fiegel, Meullenet, and Seo have found that after drinking cold (4 degrees Celsius) water, people were less likely to enjoy their chocolate: they found it less sweet, less chocolatey, and less creamy than when they drank room temperature (20 degrees Celsius) or hot water (40 degrees Celsius). Mony and her companions believe that this is due to TRPM5, a taste-receptor present in our tongues. TRPM5 is activated by a certain level of heat, and if it's not activated – such as when we drink cold water before a meal – we're less sensitive to sweets! 

So what does this mean? Well, have you ever been to China? If you have, you might've noticed that when you ask the waiters for water, they give you room temperature water. If you want to have cold water, you have to specify - "water with ice"! If you haven't, just think back to the last time you ate at a Japanese or Chinese restaurant -- what did they serve you? They probably gave you some hot tea to start off your meal. In Asia, meals are usually taken with hot tea or soup, and warm water, so the flavors are so much richer. But in North America, what do you always get when you order a sugar-filled burger from McDonald's? A cold glass of coke, that's what.

If you always drink cold water before you eat, then you probably don't think your food is sweet enough. If you don't think your food is sweet enough, then you'll add more sugar -- once or twice might not seem like a lot, but what if you did this every time you ate? What if your whole family, your whole city, your whole nation did this for every meal?

Now, this is only one study, and one study won't change the world. This doesn't mean that every weight-loss program and calorie-counter should start drinking warm water -- every study has its drawback. This one was conducted purely on North Americans, for example, so you don't have a worldwide pool of samples. They also found that the water temperature had absolutely no effect when they tested it with cheese, or salts in general. Still, the study has been done and confirmed by other scientists. If nothing else, the next time you try out a new brand of chocolate, think to yourself -- what did I just drink?

References

Mony, P., Tokar, T., Pang, P., Fiegel, A., Meullenet, J. & Seo, H. (2013). Temperature of served water can modulate sensory perception and acceptance of food. Food Quality and Preference. 28(2), 449-445. Arkansas, USA.

Talavera, K., Yasumatsu, K., Voets, T., Droogmans, G., Shigemura, N., Ninomiya, Y., Margolskee, R.F., & Nillius, B. (2005). Heat activation of TRPM5 underlies thermal sensitivity of sweet taste. Nature, 438(7070), pp. 1022-1025.

Wel