Question

Part 1: What mechanism may explain the negative association between having low body fat and fertility? Provide one mechanism for males and one for females.

Part 2: Should health care providers suggest weight loss for all individuals with BMIs over 30 looking to become pregnant?

Answer 1

1) Low level of fat in female may lead to anovulation and amenorrhea due to reduced hypothalamic production of gonadotropin- releasing hormone. This mechanism is known as Hypothalmic amenorrhea. It may also leads to reduced levels of follicle - stimulating hormone and leteinizing hormone from the pituitary gland. Most likely to occur in women with restricting type eating disorders and female athletes who maintain a low body weight.

Underweight men with low levels of body fat have lowered libido and reduced sperm production which may affect fertility.

2) Yes, health care provider should suggest weight loss for all individuals with BMI over 30 looking to become pregnant.

BMI over 30 decreases fertility in both male and female. Obese women have increased estrogen, androgen and leptin( decreases appetite). As a result, menstrual cycle is irregular or menstruation without ovulation. Obese males have lower testosterone and increased estrogen and leptin levels, resulting in reduced sperm production and increased erectile dysfunction.