Spidey, not a problem... I don't have a lot of time to write at the moment, as i'm at work... But hopefully this will answer any questions you have. If not, feel free to ask.
The first thing you need to understand is aspartame as an artificial sweetner is used not for health reasons, but because of politics. I know, you're saying "what?"... It's true. You see, aspartame is used in diet drinks only in north america. In the rest of the world, (australia, uk, south america, etc.) they use stevia as their natural sweetner for diet drinks, chewing gum, etc. But you see, stevia is produced in paraguay, so it is an import. With alternate sweetners being a $1.5 billion year (usd) market, it makes economic sense to keep that money in the americas. Aspartame, although it holds high health risks... Is produced in the us and keeps the money within the american economy. I will explain this a little further in the stevia section. Here's a quick explanation on your three artificial sweetner choices.
aspartame (nutrasweet/equal)
the active ingredient in nutrasweet (the pink packets) is aspartame. Aspartame is a an synthetic sweetner, if i'm not mistaken... Consisting of l-aspartyl-l-phenylalanine menthyl, ester). (also note that equal is also just aspartame. But adds dextrose [sugar] and maltodextrin) the aspartame breaks down to methanol (a type of alcohol), then quickly converts again to formaldehyde. There is no conversion to glucose. However, formaldehyde is toxic to the body and after extended use can bind to proteins in your liver, kidney and brain tissues which can cause migranes, tremors, depression, and in after even more use eye damage, seiures, kidney failure, and recently concluded brain tumors.
Yes.. Nutrasweet is good, no conversion to glucose... But it's not something you should consider as a long-term alternative. So what can you use?
stevia
look for stevia. It's a noncaloric / non-synthetic natural sweetener. And has still not been related to any health problems at all. You won't be able to find it at the supermarket, get it from your health store. It's marketed as a nutritional supplement simply to get around the fda. Do your research on stevia...It's 300x sweeter than sugar, been around for decades, doesn't cause cavities, suitable for diabetics, is very popular in countries like china and japan. (in fact, the majority of their diet drinks (including coca cola) use stevia instead of nutrasweet...)
the reason stevia is not approved by the fda is simply because it's not produced in the us, it comes from paraguay. High-intensity sweeteners constitutes a $1.5-billion/year market, which would make more economic sense to keep in the u.S. It has only been approved for reception to u.S. Vitamin stores in 1995, however they are not allowed to mention anything about the 'sweetness' of stevia on the product labels.
splenda
splenda is not a natural sweetener, in fact it is a chemically modified version of sucrose. They took the hydroxyl from sugar molecules and replaced them with chlorine atoms. (this is how they can advertise splenda as a low-calorie sweetener made from 'sugar' and tastes like sugar.) basically, it just makes the bond so strong that the body is unable to absorb the vast majority of it. It simply goes in, and is excreted in the urine. Since it can't be broken down, this also means the bacteria in your mouth can't convert it to acid, which in turn means less cavities. Look 'ma no cavities!
Is it safe? Well, think about it... Even if it isn't safe --- most of it is not even absorbed by the body. And since it's extremely sweet, you don't need a lot of it. It is 600x sweeter than sugar, and naturally has no calories at all. (sugar is a carbohydrate) but since it's so sweet, they had to add a carbohydrate carrier to cut the sweetness, which then adds around 2 calories per teaspoon. This is still minimal though.
Splenda has been approved only 7 years ago in the u.S., however no side effects have been publically discovered in that time. It took the fda 20 years of research before this approval took place, which included reviewing data from research on 110 humans and animals. Splenda has been approved in canada since 1991. However, is still pending review in most european countries.
conclusion
nutrasweet is obviously a very bad choice, no matter how you look at it. Equal is the same. Splenda has some fairly bad side effects in large doses and is the most inexpensive sugar alternative. Stevia is the best choice, however you have to buy it at a health food store... And it's expensive. Now you're informed... The choice is yours.
Justin