The author of a new book about breasts says that the average breast size is getting bigger. Florence Williams, who wrote "Breasts: A Natural and Unnatural History," reports that the average cup size is now a C and that many lingerie stores routinely carry KK-sized bras.

According to ABC News, Williams decided to start extensively researching breasts after she volunteered for a breast milk study while nursing her daughter and discovered her milk contained toxic contaminants.

"I realized there was so much about breasts people don't know," she told the news provider.

One thing that can be agreed upon is that both men and women are often obsessed with breast size. This obsession has its roots in history, according to the author. Williams reports that substances including glass balls, ivory, wood chips, peanut oil, ox cartilage and paraffin were used in primitive breast implants starting in the early 1900s.

Today, there are two types of breast implants regularly used - silicone gel and saline - and breast augmentation surgery remains one of the most commonly-performed cosmetic surgical procedures. According to the American Society for Aesthetic Plastic Surgery (ASAPS), more than 316,000 women underwent the procedure in 2011.

Concerns over breastfeeding are common among women with or without breast implants. Health Day reports that only a third of women are able to successfully carry out 3 months or more of breast-feeding. Women with breast implants are able to breast feed, but a study last year indicated that a large percentage of the women who had trouble breast-feeding thought that it would cause their breasts to sag. While pregnancy does cause sagging, breast-feeding does not contribute to that condition.

Women who have concerns with oversized breasts often consider breast reduction surgery. Large breasts can cause back, neck and shoulder pain, restricted movement, skin irritation and self-consciousness. A board-certified plastic surgeon could help determine if you need a breast reduction or any other type of breast surgery.