Most women won't be surprised by this finding: Less than one-third of women worldwide are satisfied with the size of their breasts.
But a new study suggests that what many women may not realize is their dissatisfaction could have implications for their health.
Surveys of more than 18,500 women in 40 countries, average age 34, found that 48% wanted larger breasts, 23% wanted smaller breasts, and only 29% were satisfied with the size of their breasts.
More troubling was the fact that women who were unhappy with their breast size said they were less likely to do breast self-examination and were less confident about detecting changes with their breasts -- two important self-care practices for the early detection of breast cancer.
"Our findings are important because they indicate that the majority of women worldwide may be dissatisfied with the size of their breasts. This is a serious public health concern because it has significant implications for the physical and psychological well-being of women," said lead researcher Viren Swami. He's a professor of social psychology at Anglia Ruskin University, in Cambridge, England.
"Breast cancer is the leading cause of female cancer-related deaths worldwide and poor survival rates are associated with poorer breast awareness," he noted in a university news release.
"Breast size dissatisfaction may result in avoidance behaviors that reduce breast awareness, particularly if a woman's breasts trigger feelings of anxiety, shame or embarrassment," Swami explained.
"Our study found a direct link between greater breast size dissatisfaction and poorer breast awareness, as seen through lower frequency of breast self-examination and lower confidence in detecting changes in the breasts, and this requires urgent public health intervention," Swami said.
The research, published online Feb. 5 in the journal Body Image, also found that breast size dissatisfaction is associated with poorer mental well-being -- including lower levels of self-esteem and happiness -- and that women unhappy with their breast size were more likely to be dissatisfied with their weight and overall appearance.
Women in Brazil, Japan, China, Egypt, and the United Kingdom were most likely to be unhappy with their breast size, according to the report. Women in India, Pakistan, Egypt, Lebanon and the United Kingdom reported the largest ideal breast size, while women in Japan, the Philippines, Germany, Austria and Malaysia reported the smallest ideal breast size.
"We also found that despite historical differences across nations, breast size ideals are now similar across the 40 nations we surveyed. This suggests that the objectification of medium-to-large breasts is now a global phenomenon," Swami said.
"Another key finding is that breast size dissatisfaction decreases with age. It is possible that older women experience less pressure to attain breast size ideals or that motherhood and breastfeeding encourages women to focus on the functional purposes of breasts rather than seeing them purely in aesthetic terms," Swami concluded.
The U.S. Office on Women's Health has more about body image.