This is probably the biggest offender people think of in foods that trigger acne. Turns out, there is some scientific research to back it up; a 2018 meta-analysis of observational studies linking acne and dairy intake found a "positive relationship" between dairy, total milk, whole milk, low-fat, and skim milk consumption and acne occurrence.
"While the mechanism of action has not been elucidated, it is probably associated with the natural and added growth hormones and growth factors in the milk itself, which trigger hormonal acne flares in the skin," Dr. Shainhouse told POPSUGAR. "Most milk is sourced from lactating dairy cows, who have high levels of circulating progesterone: insulin-like growth factor and other hormones that human bodies convert into dihydrotestosterone (DHT). These hormones can send oil glands into overdrive, which can trigger acne in susceptible people."
If you've been consuming dairy regularly and experience breakouts, she recommended giving it up cold turkey for a month or two to see how that impacts your skin. Since calcium and vitamin D are important nutrients, it's also essential to supplement with them while you're dairy-free.