Does Cold Water Help You Burn Calories? What the Thermogenesis Research Actually Says

Drinking cold water does burn a few extra calories, but not enough to count as a weight-loss trick. In a controlled study using whole-room calorimetry, drinking 500 ml (about 17 ounces) of water raised metabolic rate by roughly 30% for about an hour, and about 40% of that bump came specifically from the body warming the water up to body temperature (Journal of Clinical Endocrinology & Metabolism). So the "cold water burns more" idea has a real basis — it's just small. The far bigger metabolic story is that water has zero calories, which makes it the easiest swap you can make.

What "water-induced thermogenesis" really means

Thermogenesis is just heat production — the energy your body spends on everyday processes like digestion and, it turns out, handling a drink of water. In the study above, that half-liter of water produced a total thermogenic response of about 100 kilojoules, which is roughly 24 calories (Journal of Clinical Endocrinology & Metabolism). Some of that is the work of processing the fluid, and a meaningful slice is your body heating the water from room temperature up to about 37°C. Drink it icy instead of lukewarm and you nudge that warming cost a little higher — but we're talking a handful of calories, not a workout's worth.

Why the calorie math stays small

Do the arithmetic and the ceiling is obvious. If a large glass of water buys you around two dozen calories, even several glasses a day add up to less than the energy in a single banana. Later research also cautioned that the size of the effect varies with conditions and study methods, so the 30% figure is a real finding rather than a fixed guarantee you can bank on. The honest takeaway: cold water gives your metabolism a genuine, measurable little lift, but nobody is going to drink their way to a calorie deficit. Treat the thermic bump as a nice footnote, not the headline.

The metabolic win that actually matters

Here's where water genuinely helps your numbers: it has no calories at all, so every time it takes the place of a sugary drink, you cut real energy from your day. A single sugar-sweetened soda or sweet tea can carry well over a hundred calories, and those add up far faster than any thermic effect could ever burn off. Cold water also happens to be the drink most people find easiest to reach for in summer — and a drink you enjoy is a drink you'll choose again. The metabolism angle is a fun bonus; the swap is the substance.

How to make cold water the easy default

If the goal is to drink more water and fewer calories, make the cold version the path of least resistance. Keep an insulated bottle filled and genuinely cold within arm's reach, because temperature is a big part of why people prefer one drink over another. Front-load your fluids earlier in the day when it's easiest to keep up, and let a bottle that holds temperature for hours do the work so your water is still cold at 3 p.m. without a fridge run. None of this depends on the thermic effect — it just makes the zero-calorie choice the obvious one, meal after meal.

Keep cold water on hand

The NuRich 32 oz Insulated Water Bottle ($29.99) keeps water cold for hours so the easy, zero-calorie choice is always within reach, and the NuRich 18 oz Insulated Water Bottle ($14.99) is the grab-and-go size for the car or your bag. Explore the full lineup at the NuRich collection.

The bottom line

Cold water really does raise your metabolism a little — about a 30% short-term bump from a large glass, with a slice of that from warming the water — but the payoff is only a couple dozen calories, so it's a footnote, not a strategy. The metabolic move that counts is using calorie-free water to crowd out sugary drinks. Keep a cold bottle handy, make water the default, and let the tiny thermic bonus be exactly that: a bonus.

This article is for general informational purposes only and is not medical, nutrition, or weight-loss advice. Consult a healthcare professional about your individual needs.

Sources: The Journal of Clinical Endocrinology & Metabolism — Water-Induced Thermogenesis (Boschmann et al., 2003); PubMed — Water-induced thermogenesis (abstract).