will giving up diet coke really help me?

Yes, it is sugar free but do some research on the chemicals that are in and then make your decision. It isn't the
calories that affects you but the aspartame. It isn't good for you, health wise and losing weight wise, although once in awhile is fine.

Diet Coke is sugar free.

As people have already discussed, aspartame is a tricky one. It causes cancer, it's perfectly safe. It makes you susceptible to diabetes, it helps you lose weight. There's a lot of debate, lots of studies that show conflicting information, and some sources are completely contradictory.

For example, on the livestrong website, there are two completely different statements regarding the health effects of aspartame:

http://www.livestrong.com/article/355002-side-effects-of-aspartame-in-diet-soda/

http://www.livestrong.com/article/481292-what-is-more-harmful-aspartame-or-high-fructose-corn-syrup/?utm_source=popslideshow&utm_medium=a1

What I will say is this:

1) I gave up drinking soda (with sugar/HFCS) for one month, and after I did that, I stopped really craving it at all. I did initially lose some weight, but what I noticed more was that I just felt better overall. I never really had a taste for diet soda, so I never replaced it with that, but I do occasionally drink Vitamin Water Zero (sweetened with erithritol), Oogave (soda sweetened with agave) and Zevia (soda sweetened with stevia), and I know that it's not any better or healthier than diet soda, the sweetener they use doesn't bother me as much as aspartame though.

2) Chemicals are chemicals. I generally eat organic, spray free, grass fed, etc., so drinking soda is a bit of a stretch for me as it's way out of norm with the rest of my overall diet. I'm skeptical that drinking soda (diet or regular or alternatively sweetened) could in any way be considered healthy. I know people say not to drink your calories (iced coffee with rice milk is another weakness of mine), and I try to go by that. As diet soda has no calories, it would seem to not follow under that same line of reasoning, but then on the other hand, what is it that you're putting into your body? It has no nutritional value and doesn't provide your body anything that it needs. Whether it's healthy or not in the long run, that might be reason enough not to drink it.

3) Treats. We seem to still find ways to treat ourselves with food, or sweets/salts we know we shouldn't be eating. Maybe we rationalize that if we don't do it all the time that it's not a big deal. Once a month or so, maybe is fine, but every week, or every day perhaps stops being rarely. Though really it's all relative. If someone used to drink 5 sodas a day and is now down to 1-2, you could consider that progress. But I think we need to be real about our own self control. I could bypass a bakery and ex-nay on store-bought cookies, but if there's freshly made brownies or cookies in my house, they will get eaten, and I will blow my calorie count. It's compulsive. So I don't keep them in the house. I don't feel that I've solved anything though, since merely staying away from them has not helped my self-control when I am around them. I would say my own behavior mirrors a form of addiction, and simply changing my diet isn't going to solve that. If you feel addicted to diet coke in the sense that you don't want to give it up and you think you would feel anxious about it if you did, then giving it up for "health"'s sake might not be the right approach. You might need to look at it from the point of view of addiction.

When I dont drink it I dont have water retention.

I know the feeling.
My problems not really sugar rush but caffeine addiction and like you I don't drink hot drinks and struggle to drink water and all.
I agree with everyone else though. Try for a bit and see, it doesn't hurt to try, you can always go back to the way it was.

other than the fact that you have trained your body to "like" it and it now satisfies that learned behaviour, there is nothing else of value for your body. Once you have quit drinking it for even a short amount of time, taking a glass of it will be shocking and you will be able to taste it in a different and unpleasant way. (for me anyway)

I agree 100%. Coke was my only "vice" and it was hard to give it up, I was also addicted to the caffeine. I started by using the crystal-lite in my water that is + energy to get over the withdrawl-headache-crappy feeling.... and here I am, 3 months later and I haven't drank anything but water, water and propel-zero.... I dont miss Coke, in fact, its too sweet to me now.

I would rather eat my calories

When I was drinking 6 diet cokes/day I retained water and had energy problems.

I now drink 2/day, drink plenty of water, and have no issues with water retention.

People smarter than me with more time on their hands to be smarter than me say yes... Personally, ANYTHING that doesn't grow in the ground, from a tree, or eats something that grows out of the ground or from a tree (massive generalization) is going to have some factor of "not being beneficial."

http://www.fitday.com/fitness-articles/nutrition/healthy-eating/4-health-side-effects-of-diet-soda.html

There are other articles out there too. I think you should do your own research, consider your goals, and make a decision that YOU think will give you the best chance at reaching your goals.

I drink about 3 diet pepsi a day. When I quit drinking them, I went down one jeans size, without going down in weight. I think it was all the bloating from the sodas that I lost.

I read an article that said that people that drink diet drinks regularly consume more calories than those who don't. Even though the diet is calorie free, your body gets confused. You are consuming something sweet, but there are no calories with it. Therefore, the article claimed that your body would seek out the "lost" calories elsewhere.

I still drink them, but try to stick to one a day.

I gave it up 3 weeks ago. This is the first week I feel decent (the headaches that first week were horrible) but I do feel better in the morning when I wake up -- I no longer need to drink a diet coke first thing in the morning. And the first two weeks I also did eat sweets. This week I have noticed my cravings for desserts has reduced somewhat. This is why I gave it up. My nutritionist said there was some evidence that for some people, drinking diet coke (or other atificial sweeteners) made them crave and eat other sweets.
At first I replaced it with this Trader Joe's powdered lemonade (fast flavor sticks; like Crystal Light) but now I am moving more to plain water.
Even if I give it up entirely and manage to stay off it, I really do not want to become one of those sanctimonious ex-diet-soda drinkers; but I'd say so far I'm liking it better without!

I am shocked at all the people telling you to keep drinking it! You obviously are aware of what's in it & that it is just terrible for your insides.

I used to drink a can a day & then maybe have some when I got home too. I would get home & be ready for bed almost immediately! I was okay once I got myself to the gym but I'd have to psych myself up to getting there. Now I don't drink it at all & I have so much more energy & can actually get home & enjoy my evenings. Personally, I don't see the point of drinking something with no nutritional value, that is damaging you from the inside. You are on a health & fitness journey after all. Good luck!