The occidental diet is typically composed of high-glycemic foods, which have indicated in several researches conducted, to cause acne breakouts. These foods that have a high glycemic index (GI) include industrial sugar and starchy foods like grains, breads, cereals, milk, and processed foods.

As some studies report, the increase in the level of insulin hormone and insulin-like growth factor (IGF-1) in the human body system, produces the rise of testosterone level in men. Then, as the secretion of sebaceous glands is directly affected by testosterone, increased testosterone brings about an excessive sebum production. The oil or sebum secreted inside the organism can block the pores of the skin, forming a bacteria-friendly environment and thus triggering acne vulgaris. Also, there is an overproduction of skin cells caused by the previously mentioned hormones, further aggravating the clogging of the pores and nourishing the acne-causing bacteria.

A certain research conducted had observed that participants who only consume natural foods rather than the highly refined foods taken in an occidental diet, showed minor or no acne episodes at all.

After that, they made the same research on immigrants on westernized areas. Strangely, these people, who used to consume just natural foods and did never experienced acne before, have acquired the condition when they moved to their actual western home and have adapted the occidental diet including highly refined foods. Also, incorporating the occidental diet in young teenagers causes a sudden rise in the sex hormones, producing an even higher occurrence of acne.

Researches have also shown that too much caffeine can also elevate the levels of stress hormones inside the organism. The high amounts of these stress hormones can further trigger the acne formation, or worsen existing acne conditions. The occidental diet commonly includes high-caffeine beverages, like soda, tea, and coffee.

Other studies have also shown the importance of the high amounts of red meats and dairy products in the occidental diet to the incidence of acne skin problems. This protein diet rises the IGF-1 levels, which, as mentioned earlier, can also rise testosterone levels, indirectly over stimulating the production of sebum, as well.

Studies further demonstrate that dietary changes oriented to low glycemic carbohydrates, like fruits and vegetables, have beneficial endocrine effects that are therapeutically effective in treating acne. Such beneficial endocrine changes keep a healthy skin and a healthy growth of its cells, as well as promote normal secretion of sebum.

Although there is still no sound evidence on the relationship of certain foods in the occidental diet and acne formation, it is still best to control the amounts (neither too little nor too much) of whatever types of food that we consume.