How can mineral water have 0 calories?


I understand that obviously water does not have calories, but the water we drink is not pure and contain other nutrients and minerals on it.

How can it still be 0 calories with these nutrients added? Is it really 0 calories or is the caloric content just extremely low (therefore they round it down to 0)?

In: 0

Nutrients aren’t necessarily caloric. If there’s nothing in the water that the body can convert to use as energy, there’s no calories in the water.

Minerals don’t have a calorie content. Your body uses various metal ions and salts for creating specific proteins and enzymes but it doesn’t use them for the base metabolic process.

You can reconfigure sugar molecules into fat molecules, but you can’t turn zinc into fat.

Dietary calories measure how much stuff your body can absorb and burn. The minerals in mineral water are various kinds of salt and ash. They can be absorbed but they don’t burn.

So it really is zero.

So it may be valuable here to define exactly what a calorie **is**. A calorie is the amount of energy it takes to heat 1 gram of water by 1 degree centigrade. When we use it in food sciences, it is specifically about usable energy in food or beverages.

(As an aside, when we talk about calories in food, we are typically discussing kilocalories – so the energy required to heat 1 kg of water by 1 degree centigrade. Not important for this argument, but worth mentioning).

Not everything that we consume can actually be used as energy. That doesn’t mean they are not important for us; it just means that we don’t use them as fuel.

Iron is a good example. Iron is a critical part of how our red blood cells can transport oxygen to our various tissues and is **absolutely** critical to our survival. However, we can’t burn iron as fuel – it is a building block, but not an energy source.

So mineral water may contain a number of things, but if those things can’t be used by the body as energy, then it has zero calories in terms of nutrition.

Calories (units of energy) are obtained from three main sources: carbohydrates, proteins, and fats. Your body can also get calories from other things like alcohols. But what they all have in common is that they’re larger molecules that can be broken apart to release energy to fuel the cell’s machinery for energy production.

Minerals are usually ions dissolved in water, or they come in very simple ionic molecules that separate out when dissolved in the body. They can’t be broken for energy, they’re just used as building blocks.