Does Sugar Cause Acne? The Diet-Skin Connection

If you have ever noticed a fresh wave of breakouts after a weekend of sweets, you are not imagining things. The connection between sugar and acne is one of the most well-supported links in dietary dermatology, backed by clinical trials and large-scale studies that have accumulated over the past two decades. Unlike some diet-and-acne claims that rely mostly on anecdotes, the sugar connection has real biological mechanisms behind it.

That does not mean every piece of cake will give you a pimple. The relationship between what you eat and what shows up on your skin is shaped by your genetics, hormones, and the rest of your diet and lifestyle. But if you are dealing with persistent acne and your diet is heavy on sugary foods, refined carbohydrates, and processed snacks, there is a strong case that sugar is making things worse.

This article breaks down the science — how sugar triggers acne at the cellular level, what sugar acne actually looks like, where hidden sugars lurk, and practical steps you can take to reduce your sugar intake without overhauling your entire life.

Why Does Sugar Cause Acne? The Biological Pathway

The connection between sugar and acne is not a vague "sugar is bad for you" claim. Researchers have mapped out the specific biological pathway through which sugar promotes breakouts, and it centers on three interconnected mechanisms: insulin, insulin-like growth factor 1 (IGF-1), and inflammation.

Step 1: Sugar Spikes Insulin

When you eat foods high in sugar or refined carbohydrates — soda, candy, white bread, pastries, sugary cereals — your blood glucose rises rapidly. In response, your pancreas releases a surge of insulin to bring blood sugar levels back down. The faster and higher blood sugar rises, the larger the insulin spike.

This is where the glycemic index (GI) comes in. The glycemic index measures how quickly a food raises blood sugar on a scale of 0 to 100. Foods with a high GI (above 70) cause rapid spikes, while low-GI foods (below 55) are digested more slowly and produce a gradual rise. Pure sugar, white bread, and sugary drinks are all high-GI foods. Whole grains, most vegetables, and legumes are low-GI.

Step 2: Insulin Drives IGF-1

Elevated insulin levels trigger the liver to produce more insulin-like growth factor 1 (IGF-1). IGF-1 is a growth hormone that, among many other functions, has direct effects on the skin. Research published in Dermato-Endocrinology has detailed how IGF-1 promotes acne through multiple pathways:

• Increases sebum production: IGF-1 stimulates the sebaceous (oil) glands to produce more sebum, creating the oily environment where acne thrives
• Promotes keratinocyte proliferation: It accelerates the growth of skin cells that line the pores, leading to the buildup that clogs them
• Activates androgen receptors: IGF-1 increases the skin's sensitivity to androgens (hormones like testosterone and DHT), amplifying their acne-promoting effects
• Stimulates mTORC1 signaling: It activates the mTORC1 pathway, a cellular growth signal that further drives oil production and inflammation in the skin

Multiple studies have found that people with acne tend to have higher circulating levels of IGF-1 than those with clear skin, and that IGF-1 levels correlate with acne severity. When you eat a high-sugar diet, you are essentially pouring fuel on this fire.

Step 3: Inflammation Finishes the Job

Sugar also promotes systemic inflammation, which is the process that turns a clogged pore into a red, swollen, painful breakout. High-glycemic diets have been shown to increase levels of pro-inflammatory markers, including C-reactive protein and various cytokines. A 2018 review in the Journal of the Academy of Nutrition and Dietetics confirmed that high-sugar, high-glycemic diets are consistently associated with increased markers of systemic inflammation.

Inflammation does not just make existing acne worse — it plays a role in the formation of new lesions. When the skin's inflammatory response is elevated, minor pore blockages that might otherwise resolve on their own are more likely to develop into inflamed papules, pustules, or even cystic lesions.

What Does the Research Say? Key Studies on Sugar and Acne

The link between sugar, high-glycemic diets, and acne is not just theory — it has been tested in clinical trials. Here are the studies that carry the most weight.

The Australian Low-GI Trial (2007)

One of the most influential studies on diet and acne was a 2007 randomized controlled trial published in the American Journal of Clinical Nutrition. Researchers assigned 43 young men with acne to either a low-glycemic diet or a conventional diet for 12 weeks. The low-glycemic group replaced high-GI foods (white bread, sugary cereals, snacks) with lower-GI alternatives (whole grains, lean proteins, fruits, vegetables).

The results were significant: the low-glycemic group had a 23.5% greater reduction in total acne lesions compared to the control group. They also showed decreases in insulin levels, IGF-1, and androgen activity. The researchers concluded that a low-glycemic diet can measurably improve acne by reducing the hormonal and inflammatory factors that drive it.

The Korean Diet Study (2012)

A 2012 study published in the Journal of the Academy of Nutrition and Dietetics followed 32 participants with mild to moderate acne through a 10-week low-glycemic dietary intervention. Compared to the control group, participants on the low-glycemic diet showed significant reductions in both inflammatory and non-inflammatory acne lesions. The study also measured decreases in IGF-1 levels and sebum production in the dietary intervention group.

Large-Scale Observational Evidence

Beyond clinical trials, large observational studies have consistently supported the sugar-acne connection. A 2019 meta-analysis published in JAAD that reviewed data from multiple studies found that a high-glycemic diet was positively associated with acne. And a 2022 review in Nutrients examining diet and acne across dozens of studies concluded that high-glycemic diets and dairy had the most consistent and strongest associations with acne of any dietary factor studied.

The Kitavan Islanders study is also frequently cited in this context. A 2002 study published in the Archives of Dermatology examined over 1,200 individuals in Papua New Guinea and Paraguay who ate traditional, low-glycemic diets with virtually no processed sugar. Researchers found zero cases of acne in the study population — a striking contrast to the 80-90% prevalence seen in Western populations. While this does not prove sugar causes acne (many factors differ between these populations), it strongly suggests that the modern Western diet, with its heavy sugar and refined carbohydrate load, plays a significant role.

What Does Sugar Acne Look Like?

There is no single "sugar acne" diagnosis — acne is acne regardless of what triggers it. But breakouts driven primarily by high-sugar diets and the resulting insulin and hormonal cascades tend to share certain characteristics.

Sugar-related acne tends to be:

• Inflammatory: Red, swollen papules and pustules rather than just blackheads and whiteheads. The systemic inflammation triggered by high-sugar diets pushes breakouts toward the inflamed end of the spectrum
• Widespread: Because the insulin and IGF-1 response is systemic (affecting the whole body), sugar-related breakouts are not confined to one area. They may appear on the face, chest, back, and shoulders
• Persistent and recurring: If you are eating a high-sugar diet consistently, the underlying hormonal and inflammatory drivers are always present. Breakouts may improve briefly but keep coming back
• Oily: Increased sebum production is one of the primary effects of elevated IGF-1, so sugar-driven acne often comes with noticeably oilier skin

That said, it can be difficult to distinguish sugar-related acne from acne driven by other factors just by looking at it. The breakouts overlap heavily with hormonal acne, which makes sense — sugar worsens acne through the same hormonal pathways. If you suspect your diet is playing a role, tracking what you eat alongside your breakouts is more informative than trying to diagnose the cause from the appearance alone.

Hidden Sugars That May Be Causing Your Breakouts

Cutting back on obvious sugars — candy, soda, desserts — is the easy part. The harder part is recognizing how much sugar hides in foods that do not taste particularly sweet. Many of the biggest culprits in the sugar-acne connection are not desserts at all. They are everyday foods with high glycemic loads that spike insulin just as effectively as a candy bar.

Food	Glycemic Index	Why It Matters
White bread	~75	Spikes blood sugar as fast as table sugar; a staple in most diets
White rice	~73	A high-GI staple; large portions amplify the insulin response
Sugary cereals	~70-85	Often combined with milk (dairy), doubling the insulin spike
Fruit juice	~50-70	Marketed as healthy but stripped of fiber; sugar hits the bloodstream fast
Flavored yogurt	~50-60	Can contain 20-30g of added sugar per serving, plus dairy
Granola bars	~55-75	Often loaded with honey, corn syrup, or sugar despite "healthy" branding
Pasta (white)	~50-65	Moderate GI but often eaten in large portions, increasing total glycemic load
Soda and energy drinks	~65-75	Liquid sugar absorbs rapidly; a single can delivers 35-45g of sugar
Sweetened coffee drinks	Varies	A large flavored latte can contain 40-60g of sugar — more than a can of soda
Condiments (ketchup, BBQ sauce)	Varies	Sugar is often the second or third ingredient; adds up across multiple meals

The key concept here is glycemic load, not just glycemic index. Glycemic load accounts for both how quickly a food spikes blood sugar and how much of it you eat. A food with a moderate GI eaten in large quantities (like a big bowl of white pasta) can produce a glycemic load similar to a high-GI food eaten in smaller amounts. When you are thinking about sugar and acne, it is the total glycemic load of your overall diet that matters most — not any single food in isolation.

Does Not Eating Sugar Help with Acne?

This is the question most people really want answered: if you cut sugar, will your acne get better? The evidence says it can — but with important caveats.

The clinical trials discussed above show that switching to a low-glycemic diet leads to measurable improvements in acne for many people. The 2007 Australian trial found a 23.5% greater reduction in lesions over 12 weeks, and the 2012 Korean study showed decreases in both inflammatory and non-inflammatory acne along with reductions in IGF-1 and sebum. These are meaningful, evidence-based improvements.

But there are realistic expectations to set:

• Sugar reduction helps most when sugar is a significant contributor. If your diet is heavy on soda, sweets, and refined carbs, cutting back can make a noticeable difference. If your diet is already fairly balanced, the impact may be smaller
• It takes time. You will not see results overnight. Acne lesions already forming beneath the skin will still surface over the next 2 to 4 weeks regardless of what you eat today. Most people need 6 to 12 weeks of consistent dietary change to see clear results
• It is unlikely to be a complete cure. For most people with persistent acne, diet is one of several contributing factors. Cutting sugar can reduce breakouts, but it rarely eliminates them entirely without addressing other factors like hormones, genetics, bacteria, and skincare
• Extreme restriction is not necessary. You do not need to eliminate all sugar from your life. The goal is to reduce your overall glycemic load — fewer spikes, fewer high-sugar meals — rather than achieving zero sugar intake, which is neither practical nor necessary

Low-Glycemic Swaps: Practical Alternatives

You do not need to go on a restrictive diet to reduce the impact of sugar on your skin. Small, sustainable swaps that lower your overall glycemic load can make a meaningful difference over time. Here are practical alternatives to the most common high-glycemic foods.

Instead Of	Try	Why It Helps
White bread	Whole grain or sourdough bread	Fiber slows digestion and blunts the insulin spike
White rice	Brown rice, quinoa, or cauliflower rice	Lower GI; more fiber and nutrients
Soda and juice	Water, sparkling water, unsweetened tea	Eliminates one of the largest sources of liquid sugar
Sugary cereal	Oatmeal with berries, or eggs	Protein and fiber keep blood sugar stable through the morning
Candy and milk chocolate	Dark chocolate (70%+ cocoa), nuts, fresh fruit	Satisfies cravings with far less sugar and no dairy
Flavored yogurt	Plain Greek yogurt with fresh berries	Eliminates 15-25g of added sugar per serving
Sweetened coffee drinks	Black coffee, or with a small splash of milk	Avoids the 40-60g sugar load of a flavored latte
White pasta	Whole wheat pasta, lentil pasta, or smaller portions with protein	Lower GI; protein and fiber slow absorption

A useful general principle: pair carbohydrates with protein, fat, or fiber. Eating a sugary food alongside protein or healthy fat slows its absorption and reduces the insulin spike. An apple with peanut butter will affect your blood sugar very differently than a glass of apple juice. A slice of cake after a balanced meal will produce a smaller insulin surge than the same slice eaten on its own as a snack.

When Cutting Sugar Is Not Enough

Diet is one factor in acne — but for most people with persistent breakouts, it is not the only one. If you have reduced your sugar intake and improved your overall diet but are still dealing with acne, that is a sign that other factors are at play and it is time to work with a dermatologist.

Acne is a complex condition driven by the interplay of genetics, hormones, bacteria, and environmental factors. Prescription treatments can target these root causes in ways that diet cannot:

• Topical retinoids (like tretinoin) normalize skin cell turnover and prevent clogged pores
• Topical or oral antibiotics (like doxycycline) reduce acne-causing bacteria and inflammation
• Spironolactone blocks the androgen activity that drives hormonal acne
• Isotretinoin (Accutane) addresses persistent acne that has not responded to other treatments

At Honeydew, our providers treat all types of acne and consider dietary factors as part of the bigger picture. We offer same-day or next-day virtual appointments with board-certified dermatologists and other qualified providers who can build a treatment plan tailored to your skin — not just your diet. Learn more about our pricing and membership options.

The Bottom Line

The connection between sugar and acne is one of the most evidence-based links in dietary dermatology. High-glycemic foods spike insulin and IGF-1, which ramp up oil production, clog pores, and fuel the inflammation that drives breakouts. Clinical trials have demonstrated that reducing your glycemic load can meaningfully improve acne — and the biological mechanisms behind the connection are well understood.

But sugar is one piece of a larger puzzle. Genetics, hormones, bacteria, and skincare all play significant roles, and for most people with persistent acne, dietary changes alone will not be the complete solution. The most effective approach combines smart dietary choices — less sugar, more whole foods, fewer processed carbohydrates — with evidence-based medical treatment tailored to your specific skin.

You do not need to give up everything sweet or live on salads to see improvement. Small, sustainable changes to your diet can lower the hormonal and inflammatory load on your skin, and a dermatologist can help address the factors that diet cannot reach. If your acne has been persistent despite your best efforts, it is worth getting a personalized plan.