When a person is active, they sweat more, resulting in the loss of fluids. Also, they lose fluids from breathing, because they tend to breathe faster and more deeply. Even a person while at rest loses fluids each time they exhale.
A teen can lose body fat by eating reasonable amounts of a balanced diet. It will also help to be active, riding a bike, playing sports, or just walking more.
It's unhealthy to dehydrate yourself like some weight loss supplements do to temporarily remove your "water weight". Fluids often weigh more, but your body will try to naturally replenish what you lose.
They can help you produce more fluids for your body
None. On the contrary, it will force your body to go into crisis mode and store fluids more than it would otherwise do. Drinking enough water is part of a healthy diet.
Because they lose plenty of those as they sweat. Normally, we get enough through our food to cover what we lose through sweating, but if we're sweating (a lot) more than usually, we might need supplements.
By eating less/healthier, and by keeping more active.
Isotonic solutions are absorbed more quickly by the body and help replace lost fluids and electrolytes during exercise, maintaining hydration and performance. Hypotonic solutions can dilute the body's fluids, potentially disrupting the body's electrolyte balance and leading to issues like hyponatremia.
Yes.
When there is excess water in your body fluids, your kidneys will produce more dilute urine to help get rid of the excess water. This results in a higher volume of urine that is more clear and less concentrated.
Eat less and be more active
Eat a healtheir diet and be more active.