For years, I was addicted to diet soft drinks - yes, me. When I finally decided to kick the habit, I truly realized that is was a real addiction. The same week that I decided to quit for good, my husband's great aunt fell, broke her hip, and had surgery. When we were in the hospital during her procedure, all I could think about was the soft drink machine down the hall. I kept thinking that I'll just have one more and then I'll quit. When someone was going to the cafeteria to pick up a snack, I was tempted to ask them to pick up a diet soda for me. This was all I could think about while an 80+ year old woman was in surgery. How wrong is that? It was then that I truly realized how bad those sodas were and how seriously addicted I was. I didn't stop at the soft drink machine that day nor did I ask anyone to bring me a soda. I broke free of my addiction and hopefully my health will not suffer from the years I consumed mass quantities of the stuff.
The reason I decided to quit in the first place was the artificial sweetener aspartame (known as Equal and NutraSweet), an excitotoxin linked to numerous serious diseases. Aspartame is so widely used now that you have to be very careful and read labels of things like flavored yogurt because they often contain this artificial sweetener.
Sucralose, trade name Splenda, is another artificial sweetener that is marketed as a healthy alternative to sugar. Studies have shown it can cause cancer in mice and was recently downgraded by the FDA from "safe" to "caution." (You know that, considering all the pressure put on them by large corporations, when the FDA negatively changes a safety rating it has to be bad.)
In addition to the impact on personal health (go to the hyperlinks I've included for aspartame and Splenda to learn about the side affects), sucralose has an environmental impact. Since the human body isn't able to break down the components of this chemical, 90% of it is excreted and ultimately ends up in our drinking water and the environment. And it doesn't seem to break down once it's there, either. Who knows what problems it will cause in the long run.
For the sake of your health and the environment (so everyone else's health), step away from the pretty colored packets of chemicals. When you want to sweeten your food, natural is always better.
(Story source: http://www.takepart.com/article/2013/11/19/my-artificial-sweetener-addiction-is-hurting-the-planet)