High glycemic foods and acne: what trials show

The glycemic index is the part of the diet and acne research with the most trials behind it. Several small studies have put people with acne on a diet that raises blood sugar slowly and counted their spots. Some found fewer spots. Others found no clear change. This guide explains what glycemic index and glycemic load mean, which foods count as high, what each trial found and what the guideline groups made of them. It is part of Skinli's acne diet guide, and it gives more detail than the sugar section in does diet cause acne.

Glycemic index and glycemic load

When you eat carbohydrate, your body breaks it down into sugar that enters your blood.

• Glycemic index is a score from 1 to 100 for how fast a food's carbohydrate is digested and raises blood sugar. A 2022 systematic review in JAAD International, a journal of the American Academy of Dermatology (AAD), counts a score above 55 as high.
• Glycemic load adds the amount you eat. A 2024 study in Cureus describes it as the amount of carbohydrate eaten combined with how fast the body breaks it down. Most acne trials aimed to lower the load of the whole diet.

The AAD gives these examples:

High glycemic (raise blood sugar fast)	Low glycemic (raise it slowly)
White bread	Most fresh vegetables
Corn flakes and puffed rice	Some fresh fruits
Potato chips, white potatoes and fries	Beans
Doughnuts and other pastries	Steel-cut oats
Sugary drinks such as milkshakes
White rice

Why blood sugar might matter for acne

The AAD describes what scientists believe. A fast rise in blood sugar causes inflammation throughout the body. It also makes the body produce more sebum, the oily substance in skin. Both can lead to acne.

A second idea involves hormones. Foods that raise blood sugar fast also raise insulin, and insulin raises IGF-1, a growth hormone linked to acne. A 2018 trial tested this in 66 adults with moderate to severe acne. After 2 weeks, the group on a low glycemic diet had lower IGF-1 than the group eating as usual. The trial was too short to measure any change in spots.

The trials

Trial	Who	Length	Result
Australia, 2007	43 males aged 15 to 25	12 weeks	Spots fell by 23.5 on average with the low glycemic diet, against 12.0 on the control diet
Nutrients, 2010	58 teenage boys, 43 finished	8 weeks	Acne improved on both diets, with no clear difference between them
Korea, 2012	32 people with mild to moderate acne	10 weeks	Fewer inflamed and non-inflamed spots, and smaller oil glands in skin samples
Journal of the Academy of Nutrition and Dietetics, 2018	66 adults with moderate to severe acne	2 weeks	Lower IGF-1; spots not measured
India, 2019	84 people using benzoyl peroxide 2.5 percent gel	12 weeks	Acne improved in both groups, with no clear difference

What the positive trials show

The Australian trial was published in the American Journal of Clinical Nutrition, and the AAD describes it on its diet page. The low glycemic diet took 25 percent of its energy from protein and 45 percent from low glycemic carbohydrates. The control diet focused on carbohydrate-dense foods with no attention to glycemic index. Doctors who counted the spots did not know which diet each person followed.

The Korean trial, published in Acta Dermato-Venereologica, also took small skin samples. In the low glycemic group, the oil glands were smaller and there were fewer signs of inflammation.

Limits of the positive trials

The men on the Australian low glycemic diet also lost weight, 2.9 kilograms on average, while the control group did not. The authors wrote that further studies are needed to separate the effects of weight loss and the diet itself.

The negative trials matter as well. In the 2010 trial, the two diets differed in glycemic index, 51 against 61, and acne improved on both. The authors suggested that a longer trial, a larger drop in glycemic load or weight loss might be needed to see a difference in teenage boys. In the 2019 Indian trial, everyone used benzoyl peroxide gel, and the diet added nothing measurable to it.

The one trial in women

Most glycemic trials studied men and boys. A 2024 study in Cureus followed 50 women aged 15 to 35 in Pakistan for 12 weeks. Half received dietary counseling and advice on low glycemic foods, and half did not. In the counseling group, the average acne severity score fell from 2.68 to 1.56, and more women ate a low glycemic diet by the end. The study was small and measured diet with a questionnaire. It is one early result for women, and larger trials in women are still missing.

What the observational studies show

Observational studies compare what people eat with who has acne, without changing anyone's diet. The 2022 JAAD International review found that 77 percent of the observational studies it identified supported a link between the glycemic content of the diet and acne. It concluded that a high glycemic index, a high glycemic load and more carbohydrate have a modest effect on acne.

Examples:

• Malaysia, 2012. 44 young adults with acne and 44 without kept food diaries for 3 days. The diets of those with acne had a glycemic load of 175 on average, against 122 for those without acne.
• France, 2020. In 24,452 adults, current acne was linked to sugary drinks and to fatty and sugary products. The JAMA Dermatology authors call for larger studies.
• Poland, 2024. An online survey of people with acne linked white rice, white flour pasta, fast food and sultanas to worse acne, as the people themselves rated it.

Vegetables and the Mediterranean diet

The 2025 review describes the Mediterranean diet as high in olive oil, white meats, seafood, fruits, vegetables, legumes, nuts and wine, and low in red meat and high glycemic foods. Many of those foods appear on the AAD's list of low glycemic foods. A 2025 review in Nutrition and Metabolism pooled 5 case-control studies with 765 people. People who followed the Mediterranean diet more closely had less severe acne. The link with getting acne at all was not clear. Eating more vegetables was linked to lower odds of acne, and the authors rated the quality of all this evidence as low.

What the guidelines say

• AAD, 2024 guideline: the evidence on a low glycemic load diet is conflicting. The guideline lists the positive trials and the Indian trial that found no difference.
• NICE, NG198: the committee saw some evidence that a low glycemic load diet may improve acne. It chose not to recommend one. It named the weight loss seen in trials, the effort needed to work out glycemic load, and concern about eating disorders, because most people with acne are young and eating disorders most often start in the teenage years.
• AAD, public advice: small studies suggest a low glycemic diet may reduce acne, other studies found no link, and more research is needed.

Making lower glycemic swaps

If you want to try this, change a few foods you eat often and leave the rest of your diet alone. Examples based on the AAD's lists:

• Swap sugary drinks for water or unsweetened drinks.
• Swap corn flakes or puffed rice for steel-cut oats.
• Add beans or vegetables to meals built around white rice or fries.
• Keep fresh fruit. The AAD lists some fresh fruits as low glycemic foods.
• Count sweet cocktails and mixers as sugary drinks. Alcohol and acne covers drinking itself, and greasy food and acne covers fries and chips.
• Treat gluten as a separate question. Cutting it out has no proven effect on acne, as gluten and acne explains.

Give it 10 to 12 weeks, the length of the trials that found a benefit, and keep your skincare the same so you can tell what changed. Take photos in the same light at the start and every few weeks after. Chocolate and milk each have their own evidence, covered in chocolate and acne and milk and acne.

Avoid strict rules about food. The NICE committee's concern about eating disorders applies here. If you notice that worry about food is taking over your day, talk to a doctor. Acne linked to polycystic ovary syndrome has its own guide: PCOS acne.

A diet change works alongside treatment. The AAD says keeping skin clear requires acne-friendly skincare and acne medicine as well. For a routine built from a photo of your skin, analyze your skin.