Research
Energy balance
Underweight status (BMI < 19 kg/m2) and strenuous physical activity impair fertility by suppressing the hypothalamic-pituitary-gonadal axis, leading to longer time to pregnancy and potential amenorrhea.
If you are underweight (BMI < 19) or exercise intensely, your body may suppress ovulation to save energy. This can double or quadruple your time to pregnancy. Increasing caloric intake and reducing exercise intensity to a moderate level can help restore normal reproductive function.
GoodRefutesHIGH confidence
underweight women (BMI < 19 kg/m2) have a four-fold longer time to pregnancy than women with a normal BMI... women that exercise to exhaustion have 2.3–3 fold increased risk of infertility
Why this rating
Supported by observational studies showing significant delays in conception and increased risk of infertility.
Source
The Deep Correlation between Energy Metabolism and Reproduction: A View on the Effects of Nutrition for Women Fertility
Roberta Fontana et al. · Nutrients · 2016
DOI 10.3390/nu8020087
narrative_reviewCited 212×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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- Obesity (BMI > 30 kg/m2) significantly impairs female fertility by causing insulin resistance, altering adipokine profiles (high leptin, low adiponectin), and disrupting the hypothalamic-pituitary-gonadal axis, leading to ovulatory disorders and reduced spontaneous conception rates.Good
- Insulin resistance in obese women directly impairs fertility by stimulating ovarian androgen synthesis and reducing sex hormone-binding globulin (SHBG), leading to hyperandrogenism and ovulatory dysfunction.Good
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