3 Dairy
Dairy has been shown in a number of studies to cause acne. There are a few possible reasons for this.
One is that dairy actually has an impact on hormonal balance, being filled with hormones that are given to livestock. Seeing as hormones are large what causes acne in the first place (specifically an increase in testosterone causes the skin to produce more oil), this can simply add fuel to the fire and upset the body’s normally healthy balance. As a result, you may end up with more acne.
Dairy can also be an issue for those that suffer from lactose intolerance. This is a condition that causes the body to produce less lactase, which would normally be used to break up lactose and thereby prevent it from curdling in the body.