Expert: Carol Schlitt - 1/26/2006

Question
My wife is addicted to Diet Coke, and I'm wondering what will happen to her in the long run.  This may sound bizarre, but she goes through it, like it's needed to keep her alive.  She goes through about 12 - 24 ounce bottles a day, at least, and I'm concerned about this.  She gets really mad at me when I mention anything about it, so I just let it go. This has been going on for a few years, and it's driving me nuts.  I hope you can help me with this.

           Thanks,   Dan

Answer
Hi Dan,

Wow -- twelve, 24-ounce bottles a day?  That's 288 ounces of liquid (over 2 gallons) -- and that's a lot of liquid whether it's soda or water.  She must be spending a lot of quality time in the bathroom.

Is she drinking caffeine-free or the regular diet coke?  If it's the regular coke she's probably addicted to caffeine. Has she complained that if she tries to give it up she has severe headaches and other withdrawl symptoms?

Of course nagging her is not that answer -- it only builds a wall of contention.  She needs your support and love to show her that you are concerned about her health and want her to be around a long long time. Drinking any beverage, even healthy beverages to an extreme (and 2.25 gallons a day is extreme)is not healthy.

The only way she's going to make a change is if she believes she needs to make a change. All the nagging in the world will not change her.

Now...are their studies that show what happens to people that consume extreme amounts of diet coke? There has been quite extensive research on diet soda consumption. The question is -- can a person ingest too much of the non-caloric sweeteners used in diet soda -- aspartame (brand name NutraSweet) and sucralose (brand name Splenda. The FDA has established a safe aspartame usage of less than 50 mg per kilogram a day. This translates to a 150 lb women consuming less 3400 mg a day.  One liter of diet soda has aproximatley 560 mg of aspartame. So this would mean consuming aproximatley 6 liters of diet soda a day -- or 3, 2 liter bottles. A 2-liter bottle is about 68 fl. ounces. So 3 x 68 = 204 ounces. The FDA is saying consuming less than 204 ounces of diet soda containing aspartame is in the safe range. Your wife is consuming 288 ounces -- over the safe range.  Maybe showing her that her consumption is not in the researched safe range may help her to see that she needs to cut-back on her consumption.

Good luck, Dan.  I hope the information I have provided is helpful.

Carol C. Schlitt
Extension educator, nutrition and wellness
University of Illinois Extension