“If we were able to persuade the next cohort of 20-year-old girls that their pregnancies would be immeasurably safer and better if they lost weight by doing some more exercise, ate more sensibly and stopped smoking, what a contribution that would be.” (Professor Dame Regan UK)

Obesity has been linked to multiple medical problems including fertility issues, infertility, and pregnancy complications. Subfertility and infertility in obese and overweight women are primarily related to ovulatory dysfunction. Anovulation often results in irregular menstrual cycles. Studies have shown that 30 percent to 47 percent of obese women will have irregular menstrual cycles. The more you weigh the more likely you are to have ovulation issues and irregular menstrual cycles. Studies have shown that losing weight often leads to the resumption of ovulation, normal menstrual cycles, and increased pregnancy rates.

In both men and women, obesity has a significant negative impact on fertility: it increases infertility, and it also increases pregnancy complications. More Americans than ever before carry excess body weight which jeopardizes their health. The current obesity epidemic isn’t just limited to the United States; many developed countries are showing similar trends as their diets and lifestyles become more like life in the U.S. Furthermore, obesity during pregnancy is increasing both in the U.S. and in Europe.

Obesity and the body mass index

The body mass index (BMI) measures the ratio between a person’s height and weight to determine how much body fat a person carries. Medical professionals use the BMI, which is also found on numerous websites for personal use.

The BMI includes four classifications for assessing adults, male and female, who are 20 years old or older. Once a BMI calculation has been made, its number determines the state of health:

• 18.5 to 24.9 points = normal weight
• 25 to 29.9 = overweight
• 30 and higher = obesity
• 40 and higher = extreme obesity

Women and weight

Excess body fat has an estrogenic effect on the body, influencing how much estrogen the body produces and how the estrogen is processed. This effect is the same in overweight men as well as women. In women, it can cause the menstrual cycle to stop, rendering the woman infertile. Women who overweight are often urged to lose weight before trying to conceive.

Losing weight when trying to conceive not only improves your chances of getting pregnant but also decreases pregnancy complications. 

Men and weight

A man's weight negatively affects his sperm function and count. To improve fertility, he should do lead a healthy lifestyle, including being at his optimal weight.

Obesity and pregnancy

Excess weight affects pregnancy, too. Overweight pregnant women are at greater risk for many complications including miscarriage, cesarean delivery, gestational diabetes, and other health complications. 

In many households, the woman is the driving force behind family diet and exercise habits. Children mimic what their parents do so it is extremely important to establish healthy eating habits when children are infants and toddlers. Learning from a mother to embrace a healthy diet and enjoy regular exercise often means the children will grow into healthier adults with reduced risk of many chronic medical conditions that plague overweight adults.

Obesity prevalence in the U.S.

Findings from the National Health and Nutrition Examination Survey, conducted in 2009 and 2010, indicate:

• More than two-thirds of all American adults are either overweight or obese.
• One-third are obese.
• 1 in every 20 adults is extremely obese.
• Between ages 6 and 19, one-third of America’s children are either overweight or obese.
• 1 in every 6 children aged 6 to 19 is obese.

Weight and wage penalties

A study published by the US Department of Labor’s Bureau of Labor Statistics indicates white women in the workplace gained considerable weight between 1981 and 2000:

• 8.6% of working white women in the US were overweight in 1981.
• 4.1% were obese.
• 24.8% were overweight in 2000.
• 25.6% were obese.

The trend has continued upward since 2000. While this trend is alarming for the physical well-being of these women, it comes with economic consequences as well. The study found white women carrying excess weight don’t make as much money as white women of healthy weight. The lower pay scale begins when the overweight woman is young and continues throughout her career, with earnings dropping as she ages or gains more weight. The study involved white women only but this wage penalty is expected to affect women of other races and ethnic minorities as well.

Women’s Increasing Wage Penalties from Being Overweight and Obese (pdf). BLS Working Papers. US Department of Labor Bureau of Labor Statistics. Dec. 2007. Web. 22 Oct. 2014.