You lose weight whenever you use the sauna – according to your bathroom scales. However, you’re not really losing fat. Sad to say, it’s only water. And as soon as you have a drink, you’ll put it straight back on. It’s true that sweating and increasing your heart rate burns calories (energy), but on the other hand, the warmth gives your body energy. So using a sauna is completely neutral for your calorie count. However, if you’re a stress eater or a comfort eater, a relaxing sauna can be a great alternative to food – and thus help you lose weight.