According to Pham Thi Thanh Huyen, MSc, Department of Adult Nutrition Examination and Counseling (National Institute of Nutrition), a high-sugar diet and being overweight or obese can cause an abnormal increase in androgen levels. A sudden rise in androgen levels in both males and females, particularly during puberty, causes the sebaceous glands to enlarge and produce several times more sebum than normal.

When androgen levels increase, the sebaceous glands are stimulated to produce excessive amounts of sebum. This excess sebum combines with dead skin cells, clogging pores and creating a favorable environment for the growth of Cutibacterium acnes bacteria, leading to inflammation and acne formation.

Dr. Huyen stated that substantial scientific evidence indicates that diets high in foods with a high glycemic index, fast food, high-fat foods or animal-derived milk can aggravate acne.
Foods such as white bread, sugary drinks, candy and refined carbohydrates cause a rapid spike in blood glucose levels. In response, the body releases large amounts of insulin, which increases levels of insulin-like growth factor 1 (IGF-1) and stimulates androgen production. This, in turn, promotes sebum secretion by the sebaceous glands and accelerates keratinization of the follicular openings, leading to widespread acne breakouts.

Dietary habits, particularly among adolescents who tend to consume processed foods, fast food, sweets, sugary drinks and carbonated soft drinks, expose the skin to both endogenous hormonal influences and exogenous dietary factors. These combined effects promote inflammation and increased sebum production, making acne flare-ups more likely.

"A high-sugar diet also increases oxidative stress and damages collagen, making the skin more prone to premature aging, dullness and slower recovery after acne. A low-glycemic-load diet can improve acne considerably more effectively than a diet high in refined foods.

Without an appropriate nutritional regimen to reduce hormonal flare-ups, adolescent acne can easily leave permanent pitted scars and dark spots," the physician from the National Institute of Nutrition cautioned.