"If you're having a can of Diet Coke every day, I do think that that is slightly too much," dietitian Nichola Ludlam-Raine told me on a Zoom call in May.
I made sure the Pepsi Max on my desk was out of shot as she continued to tell me about the potential health risks of regularly consuming ultra-processed foods, which include diet sodas.
Those risks include type 2 diabetes, cardiovascular disease, certain cancers, and depression.
There's no set definition for UPFs, but they're generally regarded as foods made using ingredients and processes that wouldn't be found in a household kitchen.
"It's not just because of the UPF ingredients, it's because of the acids as well," she said. "It's not good for your teeth."
Though diet drinks are marketed as a healthier alternative, she said, "they are far from being a health drink (water is always best!)"
Ludlam-Raine recommended cutting down gradually — from daily to a couple of times a week.
She doesn't advocate for banning diet sodas or any other food or drink you enjoy. In the months that followed, I decided to try it out.
Here's how I did it and what I learned.
A big part of the reason I drank diet soda was habit — after lunch, I liked getting a chilled can of Pepsi or Coke from the fridge.
Professor Barry Smith, an expert at the University of London's Centre for the Study of the Senses, previously told Business Insider that the sound of a can opening is designed to make you crave it. I could definitely relate to that.
"If you're looking to cut down, try swapping them for naturally flavored sparkling water, herbal teas, or infused water with fruits and herbs, which can provide a refreshing alternative without the potential downsides," Ludlam-Raine said.
I looked for healthier alternatives that didn't have long ingredient lists but could still satisfy my desire for a chilled, flavorful, fizzy canned drink. I found some non-UPF fruity drinks at the grocery store (usually sparkling water with a hint of fruit juice), but they were generally more expensive than Coke or Pepsi and came in smaller packs.
All the same, having them as healthier swaps really helped me. My favorite drinks here in the UK are Dash Water, Aqua Libra, Dalston's, and Cawston Press.
At first, the fruit-infused sparkling water tasted bland to me, but over time, I came to enjoy it — so much so that I've now become sensitive to the fake flavor of anything artificially sweetened.
Pepsi Max and Coke Zero taste more sickly to me now. They're not unpleasant, but less enjoyable as they used to be.
My afternoon Coke cravings went away after a few weeks, as my body stopped expecting it.
I'd always suspected that diet sodas might lead me to crave sugary foods, but had never been sure. While I can't say there's a definite connection for me, I suspect there is.
Artificial sweeteners in diet sodas, like aspartame or sucralose, are thought to make some people crave more sweet-tasting foods Ludlam-Raine said.
On days when I don't have an artificially sweetened drink, I might be more tempted to snack on an apple and peanut butter rather than cookies.
Ludlam-Raine also warned against trying to suppress hunger with diet sodas, which can lead to binge eating later in the day. "This can disrupt balanced eating patterns and overall energy levels," she said.
I never replaced a meal with a soda and also didn't notice much of an effect from the caffeine, but I do feel good knowing that I'm cutting down on UPFs and potentially doing my future self some good.