Women: Studies show that overweight or obese women may be more likely to develop acne. Being overweight may cause a hormonal imbalance, and hormonal imbalances can lead to acne. Acne in overweight women may also be a symptom of a hormonal disease, such as polycystic ovary syndrome (PCOS). If you are an overweight woman with acne, particularly if you have noticed excess hair growth or irregular periods, be sure to speak with your doctor about the possibility of PCOS.
Men: When it comes to men, the evidence is contradictory, so we cannot say at this point whether being overweight leads to acne in men.
How Do You Know Whether You Are Overweight or Obese?
To determine whether a person is underweight, at a healthy weight, overweight, or obese, health professionals use a measure called the body mass index (BMI). BMI is calculated the same way for all ages and genders. To calculate your BMI, follow these steps:
- Determine your height in inches. For example, if your height is 5’6”, then you are 66 inches tall
- Multiply this number by itself. For example, 66*66 = 4356
- Take your weight in pounds and divide by the number you calculated in step two. For example, if you weigh 170lb, you would divide 170 by 4356, which equals 0.039
- Finally, multiply the number you got in step three by 703. For example, 0.039*703 = 27.4
The final number in step four is your BMI. According to the World Health Organization, if you are at least 20 years old, you are:
- Underweight if your BMI is 18.49 or lower
- At a healthy weight if your BMI is between 18.5 and 24.99
- Overweight if your BMI is 25 or higher
- Obese if your BMI is 30 or higher1
People younger than 20 years should look up healthy BMIs with respect to their age in the charts on the World Health Organization website to determine whether they are underweight, at a healthy weight, overweight, or obese.1
Is There a Link Between Being Overweight or Obese and Having Acne?
Only four studies have directly investigated whether being overweight or obese increases a person’s likelihood of developing acne and/or of his acne worsening. The studies, performed around the world, agree that being overweight or obese makes females more likely to develop acne or experience a worsening of symptoms. When it comes to males, the results of the studies are contradictory, so the jury is still out when it comes to males.
The first study which tried to find a link between weight and acne was published in 1956 in the British Medical Journal. The study examined 2720 male soldiers between the ages of 15 and 45 years. The researchers did not find a clear link between weight and acne in the soldiers and wrote, “We find no simple relation between any grade of acne and weight at any age…”2
A more recent study, which was published in 2012 in the Journal of the American Academy of Dermatology, also looked at BMI and several other risk factors for acne. The study was conducted at a skin disease clinic in Southern Italy and examined 205 people with acne and 358 people without acne, all of whom were 12–24 years old. The researchers found that people with a higher BMI were more likely to have acne. They noted that the link between BMI and acne was stronger in males than in females. This means that knowing a girl’s or woman’s BMI would only be slightly helpful in predicting whether she would develop acne, but knowing a boy’s or man’s BMI would be more helpful in predicting whether he would develop it.3
Another study, published in 2012 in the journal Archives of Dermatology, was carried out in Norway and examined 4744 teens between the ages of 18 and 19 years. The researchers found a link between BMI and acne in girls, but not in boys. However, despite this link in teen girls, the researchers were not comfortable with concluding that being overweight causes acne. One reason for this was that the study was based on questionnaires which the teens filled out themselves, so the researchers did not check whether the information they gave was correct. Additionally, the study only looked at the teens at one specific point in time. In order to show that being overweight causes acne, the researchers would ideally study teens who were of healthy weight, observe them over time, and determine whether those who gained weight ended up developing acne. Because of these limitations, the authors of the study wrote, “Despite the findings demonstrating a relationship between acne and overweight and obesity in girls aged 18 and 19 years, the study limitations do not allow the straightforward interpretation that obesity causes acne.”4
The last study, which was published in 2014 in the Saudi Medical Journal, studied Turkish females between the ages of 13 and 42 years. Of these females, 141 had acne and were assigned to group 1, while 73 females did not have acne and were assigned to group 2. The researchers then calculated each girl’s or woman’s BMI and determined whether she was of healthy weight, overweight, or obese. They found that group 1, the group with acne, comprised more overweight and obese females than group 2. They concluded that the higher a girl’s or woman’s BMI is, the more likely she is to develop acne. The researchers further divided just the females with acne into two subgroups: subgroup 1 contained females with mild acne, and subgroup 2 contained females with severe acne. They compared the BMI of the females in the two subgroups and found that the severe acne group possessed a higher average BMI than the mild acne group. The authors therefore added to their conclusion that not only is a female with a higher BMI more likely to develop acne, but also more likely to suffer from severe acne with a higher BMI. They wrote, “There was a positive correlation between body mass index (BMI) value and the severity of acne.”5
It is important to note that even in females, the studies did not show that being overweight causes acne. They instead showed a correlation: in other words, they showed that females who are overweight tend to suffer from acne. Another example of a correlation would be noticing that on the days when people carry umbrellas, there are usually puddles on the ground. Of course, the umbrellas didn’t cause the puddles. Instead, both the umbrellas and the puddles are due to another factor—rain. In the same way, it is possible that another factor causes some people both to develop acne and to be overweight. To show that excess weight actually causes acne, researchers would have to take people of healthy weight and without acne and randomly subdivide them into two groups: an experimental group and a control group. The people in the experimental group would need to gain weight, while the people in the control group would need to stay at the same weight. The researchers would then compare the number of people with acne in the two groups. If the people in the experimental group had more acne than those in the control group, then being overweight most likely causes acne. Until a study like this is performed, we cannot be confident that weight is the cause of acne in overweight or obese people. Rather, another factor may cause both excessive weight and acne.
Why Might Overweight or Obese People Have More Acne?
An overproduction of androgens (male hormones that are present in both males and females), are one of the top causes of acne in both males and females.
Being overweight or obese can cause a hormonal imbalance to occur. It makes scientific sense that this could then lead to acne. Here's how: In some people, excess weight causes insulin resistance. Insulin is a hormone which is necessary for our body’s cells to obtain energy from the food we eat. When excess weight causes a person to become insulin resistant, the cells of the body stop responding normally to insulin. The body reacts by producing more insulin, which, in turn, can cause the person to gain even more weight.6 Because insulin is a “master hormone,” which controls other hormones, when more insulin is produced, more androgens are produced. Androgens directly control sebum (skin oil) production, so more androgens means more skin oil is produced. And more skin oil normally leads to more acne.7 In other words, being overweight or obese may start a chain reaction, causing an increase in insulin and leading to even more weight gain and acne.
Polycystic Ovary Syndrome - A Special Case
Some teen girls and women suffer from a hormonal disease known as polycystic ovary syndrome (PCOS). The name of the disease comes from the fact that females with PCOS often have small cysts on the ovaries. Although it is normal for women to produce small amounts of androgens, women with PCOS produce too much. This leads to other symptoms of PCOS, such as acne, weight gain and obesity, hirsutism (unusual hairiness), excess sebum, and irregular periods.5,7 For instance, one of the studies we looked at above, in which researchers looked at Turkish females with acne, the researchers noticed that many more females with acne were unusually hairy, experienced irregular periods, and had cysts on their ovaries when compared to females without acne. The researchers also measured the amounts of androgens in each girl’s or woman’s blood and found that the higher the levels of androgens a girl or woman possessed, the higher her BMI and the more severe her acne was.5 Put simply, some females develop acne and also become overweight or obese because they suffer from PCOS, which causes their bodies to produce too much androgens.
A Western-style diet, filled with high-glycemic (high sugar) and processed foods, and an imbalanced ratio of omega-3 to omega-6 fats, can lead to weight gain and may therefore contribute to acne.
Some scientists have found that acne, like obesity, is a disease of Western civilization and is absent in regions where people’s diets are more “natural” or similar to those of the Stone Age.8 The Stone Age, or Paleolithic Period, which represents the vast majority of human evolution, was a time when humans lived as hunters and gatherers, and their diet consisted of meats, fruits, nuts, and vegetables, with few grains, processed foods, sugar, or dairy products. In contrast, a Western diet today, which is sometimes called the Neolithic diet, typically includes high levels of processed grains, cereals, and dairy products.
Many food products which are part of the modern Western diet have a high glycemic load, which means that they are high in sugar. Consuming these foods will cause the amount of glucose in a person’s blood to increase quickly, which can lead to insulin resistance as we mentioned previously, and an ensuing hormonal chain reaction that potentially leads to weight gain and acne.8
One method of determining how eating a particular food will affect your blood sugar is to view its glycemic index, which is measured in low, medium, and high categories.9
- Low (55 or less): The food is low in sugar and will not significantly increase your blood sugar
- Medium (56–69): The food will moderately increase your blood sugar
- High (70 or more): The food is high in sugar and will quickly increase your blood sugar
Let's look a bit more deeply into how eating high glycemic load foods might lead to weight gain and acne. Research suggests that eating foods with a high glycemic load (HGL) increases the levels of two hormones:
- Insulin-like growth factor 1 (IGF-1)
As we have seen, insulin can set off a chain reaction leading to both weight gain and acne.
IGF-1 is a hormone that has many effects on the body, one of which is to increase the production of androgens. As we have discussed, an increase in androgens can lead to more sebum production and more acne. In addition, IGF-1 can also directly increase the production of sebum even further.10
Let's dive even deeper now. A diet with a high glycemic load may cause the body to produce certain substances called binding proteins. These substances play a part in synthesizing unsaturated (normally liquid at room temperature) fatty acids. Why does this matter? Because sebum that is abundant in unsaturated fatty acid is more likely to cause acne.8
One study tried to answer the question of whether a diet with a low glycemic load (LGL) can solve the problems of both obesity and acne by putting acne patients on a 12-week LGL diet. The results were promising: the patients on the LGL diet lost more weight, produced less sebum, and experienced less acne overall at the end of the 12 weeks compared to patients who stayed on a HGL (high glycemic load) diet.11
The study, published in 2008 in the Journal of Dermatological Science, put acne patients on a 12-week LGL diet and compared them to acne patients who remained on a HGL diet. The researchers found that after 12 weeks, the patients had significantly less acne than patients who stayed on a HGL diet. The patients on the LGL diet also produced less sebum and lost more weight. In fact, the researchers found that the higher the patients’ BMI at the beginning of the diet, the more weight they lost over the 12 weeks.11
The results of this study suggest that a LGL diet may help reduce both excess weight and acne, but more research is needed to confirm this result. It is important to note that since the patients lost weight, we cannot be sure that the weight loss is not the reason their improved acne. That is to say, any diet or exercise regimen that caused weight loss could have been just as effective as the LGL diet in reducing the patients’ acne.
Recently, some scientists have speculated that weight cycling or “yo-yo dieting,” in which an overweight or obese person repeatedly loses weight and then gains it back, may also contribute to acne development.12 Weight cycling appears to cause an increase in the number of fat cells, and this sets off a chain reaction in the body. One possible result is that the body begins to produce more unsaturated fatty acid. As mentioned before, sebum that contains more unsaturated fatty acid is more likely to cause acne.13,14 However, so far, no one has conducted a properly controlled study to test this idea.
Overweight and obese women tend to suffer from more acne, while the evidence for this regarding men is contradictory. Acne in overweight or obese people may be due to increased insulin, a high-sugar diet, or a hormonal disease like PCOS in women. In addition, weight cycling may play a role, but there is currently no evidence to confirm this suspicion.
The Experts at Acne.org
Our team of medical doctors, biology & chemistry PhDs, and acne experts work hand-in-hand with Dan (Acne.org founder) to provide the most complete information on all things acne. If you find any errors in this article, kindly use this Feedback Form and let us know.
- Obesity and overweight, <http://www.who.int/en/news-room/fact-sheets/detail/obesity-and-overweight>
- Bourne, S. & Jacobs, A. Observations on acne, seborrhoea, and obesity. Br. Med. J. 1, 1268–1270 (1956).
- Di Landro, A. et al. Family history, body mass index, selected dietary factors, menstrual history, and risk of moderate to severe acne in adolescents and young adults. J. Am. Acad. Dermatol. 67, 1129–1135 (2012).
- Halvorsen, J. A. et al. A population-based study of acne and body mass index in adolescents. Arch. Dermatol. 148, 131–132 (2012).
- Alan, S. & Cenesizoglu, E. Effects of hyperandrogenism and high body mass index on acne severity in women. Saudi. Med. J. 35, 886–889 (2014).
- Kumari, R. & Thappa, D. M. Role of insulin resistance and diet in acne. Indian J. Dermatol. Venereol. Leprol. 79, 291–299 (2013).
- Halvorsen, J. A. et al. A population-based study of acne and body mass index in adolescents. Arch. Dermatol. 148, 131–132 (2012).
- Melnik, B. C. Linking diet to acne metabolomics, inflammation, and comedogenesis: an update. Clin. Cosmet. Investig. Dermatol. 8, 371–388 (2015).
- Fiona, S. A., Kaye, F. & Jennie, C. B. International Tables of Glycemic Index and Glycemic Load Values: 2008. Diabetes Care 31, 2281–2283 (2008).
- Melnik, B. C. & Schmitz, G. Role of insulin, insulin-like growth factor-1, hyperglycaemic food and milk consumption in the pathogenesis of acne vulgaris. Exp. Dermatol. 18, 833–841 (2009).
- Smith, R. N. et al. The effect of a low glycemic load diet on Acne vulgaris and the fatty acid composition of skin surface triglycerides. J. Dermatol. Sci. 50, 41–52 (2008).
- Strohacker, K., Carpenter, K. C. & McFarlin, B. K. Consequences of Weight Cycling: An increase in disease risk? Int. J. Exerc. Sci. 2, 191–201 (2009).
- Kim, J. et al. Activation of Toll-Like receptor 2 in acne triggers inflammatory cytokin responses. J. Immunol. 169, 1535–1541 (2002).
- Farah, D. M. & Ingham, E. Acne: Inflammation. Clin Dermatol 22, 380–384 (2004).