People who have a high BMI have high levels of visceral fat. Which is harmful fat that surrounds the organs in the abdomen and affects hormone levels in both men and women.
This is different from the fat which lies just under the skin (the kind you can feel if you pinch yourself), which is known as subcutaneous fat.
The impact of a high BMI is that it generally leads to more visceral fat which can lead to imbalances in the hormones that control reproduction.
The hormones testosterone and oestrogen are found in both males and females but the relative proportions are different, with men having more testosterone and women more oestrogen.
- Males – testosterone is produced in the testicles and used for sperm production. If a man becomes obese then more of the testosterone is converted into oestrogen and this reduces his sperm count.
- Females – oestrogen regulates the menstrual cycle: an increase in oestrogen causes an egg to mature and be released. A hormone imbalance can make ovulation irregular, reducing the chances of conception.
Nutrition and fertility
By reducing a high BMI many of its impacts on fertility are reversible. So even though a man’s sperm count might be low and a woman might not be ovulating there is evidence to suggest that a change of diet and an increase in exercise could mean it is possible for them to conceive naturally.
Although an increase in a certain food won’t affect fertility, a balance of healthy whole foods with a focus on macronutrients can definitely improve fertility and chances of conceiving naturally.
As well as this, a healthy lifestyle can aid the IVF process and ensure that a couple has the best possible chances of giving birth to a healthy baby.