Many of us do this each day. We know it’s not healthy but check this out 
What if I told you you were eating something every day that has been classified as “possibly carcinogenic to humans”? The strongest link is to a type of liver cancer (hepatocellular carcinoma). However, some studies have shown a possible link to an increased risk of breast cancer and obesity-related cancers.
If that’s not bad enough, it also leads to an increased risk of heart attack and stroke. Also, headaches, dizziness, and digestive issues, although the evidence is not conclusive.
What is this mystery substance? 
Aspartame 
But don’t worry, the FDA said as long as you keep it under 50mg of aspartame per kilo of body weight, you’re in the safe zone. So if a 12 oz of Diet Pepsi has 200mg, and you weigh 150 lbs, you would have to drink 18 cans to exceed that limit in one day, which is 216oz or almost 2 gallons or like drinking 3 of the Two-Liter jugs.
Yay! We’re all safe, pass the Diet Coke and a beer bong… HANG ON! We have to consider the half-life. It takes the body up to 22 hours to clear half of the aspartame that you consume from your system. So for easy math, if you drink a 64-ounce Big Gulp one day, you still have almost 32 ounces worth of aspartame in your system the next day when you slurp down another Big Gulp. Then on day 3, you’re still clearing 16 ounces from day 1, and still have 32 oz from day 2, then you drink another 64 oz big gulp. The point is, that it all stacks up. By day 4, you’re exceeding the FDA’s safe limit.
To be more clear… That’s based on a 150 lb (68 kg) adult who drinks 64 oz (5.3 cans) of Diet Pepsi every day. That’s 1,060 mg of aspartame, and I’m accounting for aspartame’s half-life of 20 to 22 hours. It would take 4 days of consistent daily consumption at that level to reach and exceed the FDA’s acceptable daily intake limit of 3,400 mg.
So is one can of Diet Coke every day of the year safe? Sure, but only if you weigh 280lbs. If you weigh 150lbs and drink pop every day, your max is 7 ounces per day AND this doesn’t account for other sources of aspartame like Sugar-free gum, mints, jello, or yogurt. So stop poisoning yourself or AT LEAST take some days off to let it clear your system.
–Weight gain – Aspartame increases your appetite, increases sugar cravings, and jacks up your gut bacteria.
