Obesity’s Impact On Male Fertility

Written by Pliro
Jul 9, 2018 Last updated: Jul 9, 2018


Obesity has truly become one of the most important topics of our age. So far, it has been related to a very very large list of pathologies, most of them chronic in nature. The definition of obesity varies with context. However, the most direct way to characterize it is as “the excessive accumulation and storage of fat in the body”. Many different biological mechanisms interact within an obese person causing small but incrementally dangerous problems that eventually manifest as diabetes, cancer, allergies, cardiovascular diseases, and other conditions.

Obesity And Male Fertility

Most people know some of the dangers of being overweight, but many don’t know that it can actually cause infertility. In this article we will briefly address some of the most important and recent findings about the impact of obesity over male fertility. For simplicity, we will use the term quality in some instances as a way to group a large and complex group of factors that are important for a male to reproduce without outside interference or extraordinary means.

For many years, this topic was controversial in the scientific community. The major reason for that was a lack of data available. Also, the techniques to measure male fertility have been evolving, allowing for better evaluation.


Large studies involving nearly 10,000 men revealed a relation between obesity and an abnormal sperm count. At the time the theory was that somehow fatty deposits interacted with the process of sperm production through some kind of hormonal alteration or some toxic byproduct of fat storage that gradually “poisons” the testicular tissue, causing reduced sperm quality.

Later, it was revealed that obesity leads to a risk of azoospermia or oligozoospermia (absence or reduced number of sperms). Making clearer that being overweight can lead to male infertility by damaging the cells that produce spermatozoids.


Now, the question was “How?” meaning, through what mechanism large fat storages causes infertility? This question still hasn’t been answered definitively, but some interesting hypotheses are gaining attention. High levels of sugar, insulin or lipids (cholesterol or triglycerides) in blood are thought to cause a decrease in in the quality of sperm. This leads to a reduced quality of the reproductive function.

Recent findings in the field of epigenetics seem to indicate that if your father was overweight a the time of your conception, then, is possible that your DNA was affected. This makes you much more likely for you to be overweight in the future. As some kind of genetic memory, the part of you that comes from your father remembers being part of a being with extra fat. This may sound odd but in reality, our DNA suffers many small and subtle modifications (not mutations). Obesity can count as a consequence of that interaction.

For now, and as usual, there are no magic cures to this situation. If you want to maximize your chances of having a child without any kind of medical intervention, changing your habits is your best option. Regulating of hormones also possible if you suffer from an hormonal disease.