As a kid, my parents would say I had an 'iron stomach'.
Spicy curry had no effect on me and I could eat as much cheese, dairy and Mexican food as I wanted.
Even when I caught sickness bugs at school, I could usually hold it in.
So you can imagine my surprise when, for the first time in my life, I began suffering extreme gas and belly aches after moving from the UK to the US a few months ago.
At first I assumed it was stress or a mild winter bug, something temporary that would go away on its own.
But this lasted weeks.
And I don't use the word 'extreme' lightly.
During these 'attacks', I would pass gas dozens of times per hour, which was not only uncomfortable physically but incredibly embarrassing.
Work meetings and restaurant dinners became anxiety-inducing.
As a kid, Charlie's parents would say he had an 'iron stomach' (stock image)
But then Charlie moved from the UK to the US and something strange happened to his gut (stock image)
At the time, there weren't any obvious triggers and there only seemed to be one pattern: the worst bouts came at night and in the morning.
It got so bad at one point my wife insisted we stagger our sleeping times.
I started going to bed 30 minutes before her so I'd be asleep (and the flatulence would stop) by the time she followed.
Something clearly had to be done.
What would I tell friends and family if our six-year relationship came crashing down because I stank out the apartment?
So I started looking even more closely at my diet — did I have an allergy I didn't know about? Was I not cooking something properly?
Adding to the confusion was the fact that I thought I was eating more healthily than ever.
I had been meticulously counting my calories every day to stay at a specific bodyweight (165lbs) for a martial arts competition I had coming up.
But that's where the problem was.
In striving to get my weight down, I had incorporated 'low-calorie' versions of popular foods into my diet.
To reduce the calorie content without sacrificing flavor and texture, manufacturers use lots of synthetic chemicals.
I honed in on two relatively new additions to my diet: a protein bar that I would mix in with yogurt and fruit in the morning and a strawberry jelly that I would have on a bagel at night as a sweet snack.
I chose the Legendary Protein Pastry bar because it had a measly 180kcal (a third less than a similarly-sized Hershey's bar, with none of the sugar).
Despite consuming this protein bar every day for weeks, I had never looked at the back of the packet.
I was stunned.
The Legendary Protein pastry was so tasty I'd have it every morning with yoghurt and fruit. But it contained 30 ingredients, many of which were linked to gut issues and worse... cancer
First of all, the bar has more than 30 ingredients (far higher than the five-ingredient rule many diet experts preach).
Its contents also read more like the stock list for a chemistry lab than food.
Erythritol, polydextrose, glycerin, modified cellulose, carnauba wax, collagen peptides, calcium caseinate, micellar casein... the list went on!
In fact, eight of the ingredients in the bar have been linked to gut problems.
Erythritol, for example, is a sugar alcohol that can cause bloating, gas, and diarrhea.
Meanwhile, polydextrose is a synthetic fiber used to puff up the volume of the bar and keep you full on few calories — but it can cause bloating, gas, and laxative effects.
Other ingredients like soluble corn fiber and the artificial sweetener sucralose have been linked to bloating and damaged gut bacteria.
But, it turned out, bloating was the least of my worries — at least seven of the additives were linked to cancer.
The colorings Red No 40, Yellow No 5, Yellow No 6, Blue No 1 and the newly banned Red No 3 have all been shown to be carcinogenic in early studies. And they were all there in that one bar.
Meanwhile, some animal studies suggest sucralose and palm kernel oil could cause potential carcinogenic effects at high temperatures (that was bad news because I’d been microwaving these bars, as suggested on the packaging, for weeks).
All but one of the coloring agents (Blue 1) are banned or heavily restricted in the European Union and my home country the United Kingdom.
Red No 3 was also belatedly banned by the FDA in January but that ruling won't take effect until January 2027.
Could it be that my sheltered stomach, having grown up in a country where we aren't exposed to so many chemicals, was sensitive to these pernicious ingredients?
I had the same horrifying reaction when I inspected the label of the jelly I'd been scoffing every night.
The Smucker's Sugar Free Strawberry Preserves contained just 10kcal per serving compared with 60kcal in the regular sugary stuff.
But that's where the positives ended. I knew it seemed too good to be true!
At least three ingredients (Red 40, sucralose, and maltodextrin) have been linked to the formation of tumors, while a few others (polydextrose, locust bean gum, potassium sorbate, and calcium chloride) have been associated with digestive issues.
The Smucker's sugar-free jelly seemed to good to be true... it had just 10 calories per serving! At least three ingredients (Red 40, sucralose, and maltodextrin) have been linked to the formation of tumors
Red 40 was the only ingredient banned in the UK.
I stopped eating both items that very day and, fascinatingly, the gut issues stopped immediately.
With so many harmful ingredients it's hard to say exactly which one caused my stomach to go haywire. Perhaps it was a combination of several.
I still have an extremely sweet tooth that has to be satisfied, so I've had to make smarter choices.
Honey has replaced the jelly on my nightly bagels and I swapped the protein cake for an RX bar that contains just a handful of natural ingredients: dates, egg whites, nuts, chocolate and sea salt.
I can't eat as much because they are higher in calories, but that's a sacrifice I'm willing to make for my gut... and my marriage.
The company that makes the jelly, JM Smucker Co, told me: 'Please know that delivering safe, quality products is our top priority and our continued ability to meet that commitment has earned us the trust of consumers.
'As part of these efforts, we regularly evaluate our ingredients to ensure they abide by all established regulations and meet the needs of our consumers.
'The ingredients referenced have been confirmed as safe to consume and comply with FDA regulations.
'As always, we will ensure that all of our products continue to align with all regulatory requirements while monitoring consumer preference to ensure we continue to deliver on their needs.'
I also reached out to Legendary Foods for comment but did not hear back.