Does sugar cause acne?

This one has reasonable science behind it. Diets high in high-glycemic foods — sugar, white bread, sugary drinks — spike blood sugar and insulin, which raises IGF-1 and androgen activity and can worsen acne. Randomised studies of low-glycemic diets have shown improvements in acne.

Sugar isn't the sole cause of acne, and a single dessert won't break you out. But a consistently high-sugar, high-glycemic diet is a plausible aggravator worth addressing alongside your skincare.

What the research says

This is one of the better-evidenced diet links. Randomised controlled trials of low-glycemic-load diets — notably Smith et al. (Am J Clin Nutr, 2007) — have shown measurable improvements in acne compared with high-glycemic diets.

High-glycemic foods spike blood glucose and insulin, which raises IGF-1 and androgen activity and drives sebum. It's the overall glycemic load of the diet that matters, not a single sugary treat.

What you can do

• Shift toward lower-glycemic foods (whole grains, protein, vegetables).
• Cut back on sugary drinks first — they're the biggest, easiest win.
• Give dietary changes 8–12 weeks; skin is slow to respond.

Bottom line

A consistently high-sugar, high-glycemic diet is a credible aggravator of acne, backed by randomised trials. Cutting sugary drinks first is the biggest, easiest win.

Vet your skincare too

Diet is only one piece. Many breakouts are driven by what you put on your skin. Paste your products into our comedogenic ingredient checker to rule out pore-clogging ingredients, and check for fungal-acne triggers if your bumps are small and itchy.

Sources & further reading

• Smith RN, et al. A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Am J Clin Nutr. 2007.
• American Academy of Dermatology — acne resources

By Mitchell Zandwijken · Last updated July 2026. See our sources & methodology.