Remember those whispers during high school that chocolate would give you acne? We hate to break it to you, but there might be more to it than urban legend. And what's worse, it's not just chocolate, but all sugar-laden foods are to be blame: from macarons to cakes and cronuts. That's right: too much sugar is affecting your skin as well as your waistline.

"According to a report published in the Archives of Dermatology, high glycaemic index foods cause large fluctuations in your blood sugar levels and have been linked to the development of many health problems," says Heather Vounnou, national training manager at Ella Bache. What exactly are high GI foods? Basically all the sweet stuff just mentioned, as well as anything made with refined sugars or overly processed, from white bread and many breakfast cereals to lollies and alcohol.

The single ingredient that’s ruining your skin

How could something so sweet cause so much damage? For all us sweet tooths out there, the science is scary. "Sugar consumption increases blood levels of the androgen hormones," says Vounnou. "The increase in androgen hormones directly stimulates the sebaceous gland to produce more of a thick, sticky type of sebum, which clogs the sebaceous follicle, leading to acne development."

It gets worse: not only is excess sugar consumption linked to breakouts, but to dullness, dehydration and premature ageing, care of a process called glycation. In basic terms, glycation occurs when sugar bonds with collagen in the body, damaging the collagen fibre. "Collagen forms the main support structure in the deeper layers of our skin and gives the skin its firm, youthful appearance," says Vounnou. "The more High Glycaemic foods you eat on a day-to-day basis, the more damage is done to this collagen, damaging the skin's support structure." And the result? Wrinkles. 

Of course, the occasional cronut never did anyone any harm (and hey, the wrinkles might even be worth it). But if you've over-indulged lately, take heart: it's never too late to reverse the damage. Cutting back on the white stuff will set you back on the path to complexion perfection in as little as three weeks. "The older you are and the more damage you have, the longer it's going to take to repair and rebuild," says Vounnou. "On average it should take about two months, but some individuals notice a difference after three weeks." That calls for a celebratory slice of chocolate cake in our book (just don't tell your dermatologist). 

The single ingredient that’s ruining your skin