My life mate drinks 3 or more diet colas a day, Would it be better to drink regular soda?

Your friend may not drink diet soda ever again after reading this website and the subsequent one included. Neither is good for you. Water is better.

Diet Soda Ingredients (http://www.xomba.com/diet_soda_ingredients)

Tick

Aspartame is terrible for you! It's one of the ingredients in diet drinks. If your friend absolutely needs a soft drink they are better off drinking a regular soda a few times a week.

Anything not in moderation can be harmful.
Diet soda has chemicals in it, and regular soda has sugar in it.
Neither one has positive health benefits, you could try drinking two a day of diet and one regular for a couple days, then 1 diet 2 regular for a couple, then 1 of each, then just one regular, then one regular every other day, etc .

The acids in any soda, diet or not, aren't good for you.

What? Its OK to use soda to clean a corroded car battery (it works) but it won't do damage to you?

It'll tear at your teeth enamel, and you cannot get this back. Again... diet or not.

And there is fairly solid research linking diet soda consumption to a potential "sweet tooth" problem. Meaning if a sweet drink is what floats your boat, you are also more likely to seek out other sweet treats.

And then there is caffeine.

Look.

Answer me this... what benefit does drinking soda (diet or not) give you? Outside of the very temporary mental relief?

Push me to the wall. Show me how its good for your body. Convert me.

Soda is not healthy for people. But there may be a better chance for you to stop/reduce your intake of it, by gradually adjusting to the change in your diet by drinking less and less of it until you either don't drink any or drink a small amount of it. It is often suggested in health, that to have a healthy diet you should eat healthy, exercise regularly, and eat things in moderation.. but also once in a while eat something like a piece of chocolate or a piece of cake or french fries. The need for soda for you could be partly a mental reliance, where you could substitute it for another food/drink such as something that tastes similar, or something that basically replaces it [soda] and is similar in the amount you use it or another way.. you could start chewing gum [but there is the problem-sugarless gum [chemicals] or sugar gum [... sugar], you could drink juice like orange juice every morning. I would recommend try lessening your intake first.