Do Diet Sodas Help You Lose Weight?

I am a recovering Diet Coke addict.  You may think Diet Coke addiction is not a real thing, but I can assure you my addiction met all of the medical definitions of an addiction.  I started drinking Diet Coke in high school, around the time it was reaching peak popularity.  In college and all through medical school, Diet Coke served as my main form of caffeine.  By the time I reached medical school I craved, no – NEEDED, a Diet Coke to start off my day. 

This type of addiction was always viewed by others as no big deal, and we would laugh about it as though it was just one of my quirks.  My husband actually bought me a small refrigerator for my closet so I would not have to even go downstairs in the morning to get a cold Diet Coke.  I even had Diet Coke pajamas!

Other than the ridiculous cost of my Diet Coke habit (I estimate it was costing $1000 per year, even on sale!) what is the big deal?  Diet Coke, and other diet sodas contain artificial sweeteners or “non-nutritive” sweeteners such as aspartame, sucralose, and stevia.  They contain no sugar, and have no calories.  Diet Sodas are approved by the American Diabetes Association for diabetics, and the FDA has also approved them as food additives.  On the surface, these seem like a great idea to reduce sugar intake and lose weight.  This is exactly how I got hooked, I believed they were safe and would help me stay thin.  Unfortunately, this is just not the case. 

If you have read my prior information, then you know that weight gain is linked to insulin levels.  Insulin is the hormone that puts us in storage mode, and tells the body to store excess calories as fat.  When insulin is high, the body does not use stored fat for energy.  Non-nutritive sweeteners may not have sugar or calories, but they do cause a huge spike in insulin levels for many people. 

Several studies have been done using volunteers who ingested non-nutritive sweeteners and then had their blood levels checked for glucose and insulin at multiple intervals afterwards.  After consuming the diet drinks, insulin levels were raised, and stayed elevated longer than with sugar alone.  Additionally, they ended up consuming more calories during the day to make up for the calories saved by not drinking the diet soda. 

I used to have 1-3 cans of Diet Coke in the afternoon to get through the slump that would inevitably come after lunch.  It turns out this was not helping me stay thin at all.  My insulin would spike, and I would be in fat storage mode all afternoon.  I would also get hungry and eventually give in to cravings and start eating as well.

What does this mean from a healthy lifestyle standpoint?  If you are drinking Diet Coke to stay thin and avoid calories, it just doesn’t work.  In fact, the insulin spikes are likely causing you to gain slightly more weight than if you just had a regular sugar filled soda.  We haven’t even discussed the issues of potential cancer risks from some of the chemicals that are added, but the controversy surrounding the safety of these sweeteners is concerning as well. 

The issue with the non-nutritive sweeteners is not just with diet sodas, but also with other “diet” foods as well.  Low calorie yogurt is also touted as a health food, but has the same effect.  Sugar free candy, sugar free ice cream, low sugar cookies, “skinny” or sugar free syrups at Starbucks, etc – the list goes on.  These will not help you lose weight.

Quitting Diet Coke was extremely difficult for me.   I had a long slow process of cutting back by one can a week over a period of 2 months.  I had to add in other drinks to replace it, and unfortunately I just don’t love plain water.  Here are some alternatives to soda:

·       Green tea (my favorite – shown to have appetite suppressant properties)

·       Herbal tea

·       Infused water with lemon or other fruits

·       Coffee – black or with full fat cream added

·       Bone broth

·       Carbonated plain water, seltzer water

For many people, changing what you are drinking during the day can be one of the hardest challenges.  The good news is that most alternatives are actually cheaper.  If you are having an occasional diet beverage, or 1 diet beverage per day, it is likely not a big deal.  However, if you get to the last 10 lbs or so, and hit a plateau, you may consider cutting out your diet beverage.  If you are drinking several diet drinks each day, then I would recommend cutting back to only one per day immediately.  Finally, the important thing is that once you go on the low carbohydrate diet, that you do not start to increase your intake of “sugar free” or “diet” foods, as they will not serve you in obtaining your goals.