There is little evidence that specific foods cause infertility. There was one study (link below) published in the journal Human Reproduction that looked at diet and fertility in 18,000 women without a history of infertility who were trying to conceive or got pregnant in an 8 year period. Women with a high intake of low-fat dairy foods (skim or low-fat milk, yogurt, cottage cheese) were more likely to have infertility associated with problems with ovulation (egg release) than women who ate full-fat dairy. Women who don’t ovulate don’t have regular periods, so this finding may not apply to women with regular cycles. The lowest risk of infertility due to anovulation was in women with at least one serving a day of high-fat dairy – defined as whole milk, cream, ice cream, cream cheese or other non-cottage cheese. Yes, ice cream – this should be the most popular fertility study in years. Of all the high fat dairy choices, whole milk appeared to have the strongest effect in this study.
Extremes of body weight are associated with reduced fertility. Body Mass Index (BMI) is not a perfect measure of being overweight or not (it doesn’t work for someone who is ‘all muscle’) but a healthy range for fertility is about 18.5 to 25. The ability to get pregnant may fall more at a BMI of 35 and above, although many women can conceive even in this range. See the link below for a BMI calculator.