Understanding the Connection Between BMI and Fertility

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For many, the journey to starting a family can be complex and sometimes challenging. Many factors contribute to fertility, and one of those often discussed is Body Mass Index (BMI). It's essential to understand that this is just one aspect of a broader picture and not a standalone determinant of fertility. Also, let's remember that everyone is unique, and bodies come in all shapes and sizes - what's most important is health.

BMI is a measure that uses your height and weight to work out if your weight is healthy. Research has shown that a BMI outside the 'healthy' range (18.5 - 24.9) can be associated with potential fertility issues in both men and women. That said, BMI is an imperfect measure and does not take into account muscle mass, bone density, or overall health and wellbeing.

BMI and Female Fertility

For women, having a BMI either below or above the healthy range might potentially impact fertility. An extremely low BMI might lead to irregular menstrual cycles or even a complete absence of periods. This can make it difficult for women to conceive naturally as ovulation may become irregular or stop altogether.

On the other hand, a higher BMI has been associated with polycystic ovary syndrome (PCOS) and insulin resistance, both of which can affect ovulation and thereby potentially impact fertility.

BMI and Male Fertility

When it comes to men, research indicates that a BMI outside the healthy range may also impact sperm quality and quantity, thereby potentially affecting fertility. An elevated BMI has been linked with lower sperm count and motility and increased DNA damage in sperm.

It's important to remember that the 'healthy' BMI range is a broad one, and it's not about striving for perfection. Any positive changes towards a healthier BMI are beneficial. This is about improving your overall health and, if you're planning to conceive, giving your body the best possible conditions for conception.

While BMI is one piece of the puzzle, supporting your fertility involves a holistic approach that encompasses diet, lifestyle, and supplements.


Adopt a balanced, nutrient-dense diet that incorporates a variety of whole foods, including fruits, vegetables, lean proteins, and healthy fats. It can support hormonal balance, regulate your menstrual cycle, and provide the nutrients necessary for healthy sperm and ova.

Why not grab your free "Eat Yourself Pregnant" download here. This contains a number of recipes from Zita's Eat Yourself Pregnant book.


Lifestyle factors like exercise, stress management, and sleep are essential. Regular exercise can help maintain a healthy BMI, reduce stress, and improve overall wellbeing.

Prioritising sleep and finding stress management techniques that work for you are also beneficial. Consider our guided meditations for fertility here.


Supplements can play a pivotal role in supporting fertility by ensuring your nutrient reserves are adequate to support reproductive health

We recommend high-quality preconception support, such as Zita West Female Foundation Fertility Support Pack for women and Zita West Male Foundation Fertility Support Pack. Both packs contain all of the supplements we recommend for trying to conceive. All of the supplements have been specifically formulated to be taken alongside one another. 

We also have a number of support packs for every stage of fertility journeys, such as IVF and FET, as well as specialised support packs such as our supporting pack for PCOS, and our Ultimate Egg Health Pack. Shop our range here.

To learn more about what nutritional supplements might be right for you, book a free 1:1 consultation with our inhouse nutrition team here.

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