Whichever holds true, the fact is that you need to make sure that you're getting water. Our bodies consist of a large amount of water, and will let us know when we're not getting enough. You also want to make sure not to overdo it at the same time, because there is a such thing as water poisoning.
Getting enough water helps to flush toxins from our bodies including our vital organs. The benefits include clearer skin, less fatigue, and a better chance that we'll consume fewer calories.
There are some things I notice that happen to my body when i'm not getting enough water such as yellow urine. The more yellow it is, the more dehydrated. I also notice that I may have little bouts of dizziness or a mild headache. Please do note that these can be symptoms of other health complications, so be sure to have a doctor rule out the possibility that anything else is the cause.
I know that bottled water is a big deal for many. That was our way to go up until recently. I've been hearing some negative things that have really swayed me from purchasing pre-bottled water. My husband, whose job requires that he do a lot of walking and manual labor, decided to purchase a water bottle that he can easily refill. I decided I want to get one too, and just seeing it serves as a reminder to drink water. It's even gotten to the point that I want water without seeing it, which I count as a good thing. I do recommend the use of a water filter to remove at least some of the contaminants.
This is the bottle that we have, which we purchased at Walmart
I like the size and the style of it. It holds 28 oz. It's designed so that it could hold a freeze stick
(sold separately), it's BPA free (very important in my decision making), it has a mouth big enough that I can see to it being cleaned well (to prevent bacteria growth), it has the loop on the top which makes it easy to carry or perhaps even hook onto something. I also like that it has a straw, or you could remove the straw if you'd like and just turn it up to drink from it.
This bottle is double walled, prevents condensation and is designed for hot and cold fluids. I did have to return the first one that i'd originally purchased because it was defective. It would get plenty of condensation and water was getting between the inner and outer walls, but since exchanging it, everything seems fine so far. This bottle ran us right at $5 and so far is proving to be totally worth it. As far as testing to see how hot or cold holds up, I haven't really done much. So far i've only used it for cold water, which seems to be reasonably kept cool.
This was my personal decision for a water bottle and no i've not been paid or even asked to share this with you. Hopefully, though, this will help if you had no idea of what to look for when purchasing a bottle intended to be reused. What's most important is making sure you're getting enough water :).