By Sue Bedford (MSc Nutritional Therapy
When trying to conceive — whether naturally or through IVF — nutrition plays a far greater role than many people realise. One of the most overlooked factors? Blood sugar balance.
Excess refined sugar doesn’t just affect weight or energy levels. It can disrupt hormones, increase inflammation and impact both egg and sperm health.
Here’s what you need to know
What Is Sugar — And Why Does It Matter?
Sugar is a type of carbohydrate. All carbohydrates are broken down into glucose, which provides energy for the body.
Sugar occurs naturally in foods such as fruit and dairy. However, the concern lies with refined sugars — including white table sugar, high-fructose corn syrup, sweets, pastries, sugary drinks and many ultra-processed foods.
In the UK, adults and children over 11 are advised to consume no more than 30g of free sugars per day (roughly seven sugar cubes). Many exceed this amount without realising.
Signs of Poor Blood Sugar Control
If blood sugar levels are unstable, the body can struggle to regulate insulin effectively. Symptoms may include:
- Headaches
- Feeling shaky when meals are delayed
- Poor concentration
- Mood swings
- Fatigue
- Weight gain (particularly around the abdomen)
- High blood pressure
Over time, poor glucose control can contribute to insulin resistance — a key factor in hormonal imbalance.
How Refined Sugar Impacts Fertility
1️⃣ Hormonal Disruption
Our reproductive hormones work like a finely tuned orchestra. Excess refined carbohydrates cause repeated spikes and crashes in blood sugar, leading to increased insulin production.
When blood sugar drops rapidly, the adrenal glands release cortisol and adrenaline. If this happens frequently, stress hormones rise and can interfere with reproductive hormones such as:
- Oestrogen
- Progesterone
- Testosterone
- DHEA
Over time, this imbalance may affect ovulation and sperm production.
2️⃣ Insulin Resistance and PCOS
Insulin is produced by the pancreas to move glucose from the bloodstream into cells for energy. Constant sugar spikes can lead to insulin resistance — where the body becomes less responsive to insulin.
Insulin resistance is strongly associated with PCOS (Polycystic Ovary Syndrome), a leading cause of ovulatory infertility in the UK.
Excess insulin can:
- Disrupt ovulation
- Affect egg maturation
- Increase androgen levels
Nutrients such as myo-inositol have been shown to support insulin sensitivity and ovulatory function in women with PCOS. Always seek personalised advice from a qualified practitioner.
3️⃣ Inflammation and Immune Function
High sugar intake promotes inflammation and may reduce immune resilience. Chronic inflammation can negatively affect implantation and overall reproductive health.
Refined sugar consumption also depletes key fertility-supporting nutrients, including:
- Magnesium
- B vitamins
- Vitamin E
All of which are essential for hormone balance and egg and sperm health.
4️⃣ Sugar and Male Fertility
Fertility is not just a female issue.
Research has linked sugar-sweetened beverages with lower sperm motility and reduced semen quality in otherwise healthy young men. Energy drinks and soft drinks have also been associated with poorer reproductive outcomes.
Since sperm regenerates approximately every 72–90 days, dietary improvements can positively impact sperm quality within a few months.
Practical Nutrition Tips to Balance Blood Sugar
Small, consistent changes can make a significant difference.
Focus On:
- Combining protein with carbohydrates (e.g., eggs with seeded toast and avocado)
- Healthy fats (olive oil, nuts, seeds, oily fish)
- Low glycaemic load (GL) foods
- Wholegrains and legumes
- Leafy greens and root vegetables
- Chromium-rich foods (broccoli, turkey, whole grains)
- Three balanced meals daily
- Staying hydrated
If you crave something sweet, opt for low-GL fruit such as berries, apples or pears rather than refined snacks.
Limit:
- White bread, pasta and rice
- Sugary cereals
- Cakes, pastries and biscuits
- Sugary drinks and energy drinks
- Highly processed snacks
- Artificial additives
Lifestyle Matters Too
Blood sugar control isn’t just about food.
Regular exercise (30 minutes at least four times per week), good sleep (7+ hours per night), stress management and reducing alcohol intake all play important roles in supporting reproductive health.
Even one night of poor sleep can increase blood sugar and insulin levels the following day.
Healthier Sugar Alternatives
If needed, consider natural alternatives such as:
- Stevia – plant-derived, does not spike blood sugar
- Xylitol – plant fibre-based sweetener with a lower glycaemic impact
These may be particularly helpful for individuals with PCOS or insulin resistance.
The Bottom Line: Sugar and IVF Success
Fertility is influenced by many factors — age, medical history, genetics and lifestyle. However, blood sugar balance is a foundational piece of hormonal health.
By reducing refined sugar intake and focusing on stable energy and nutrient-dense foods, you create a more supportive environment for:
- Ovulation
- Egg quality
- Sperm health
- Implantation
- IVF outcomes
Nutrition is not about restriction — it’s about optimisation.
If you would like personalised support, Sue Bedford offers Fertility Nutritional Therapy consultations tailored to your individual needs.
If you have any questions about this topic or anything else on IVFbabble, we’re here to support and guide you—our team and leading global experts are here to help. You’re not alone.
