Menopause App

Digital Packs Banner Digital Packs Banner

Expert Chat

Is sugar ruining your fertility?

Ditch the chocolate, sweets and biscuits if you’re trying for a baby. Leading fertility expert, Zita West, explains how sugar could be ruining your fertility

As a practising midwife and fertility expert, I have always been fascinated by the role nutrition takes in every couple’s ability to have a healthy, happy baby.

What I see in my fertility clinic, The Zita West Clinic, is women know everything about ‘diet’ but very little about nutrition. They will be looking for a magic ingredient in their diet that will get them pregnant, but in reality, every part of the diet and the micronutrition within it lays the foundations for a healthy – or not so healthy – egg and sperm.

Over the course of my many years in this field, I have come to the conclusion that micronutrients play a big role in getting pregnant – both naturally and through assisted conception – with deficiencies having significant effects on fertility for both men and women.

I have come to the conclusion that micronutrients play a big role in getting pregnant

2016 was the year of Brexit, Trump and the year that sugar became public enemy number one. And not unreasonably so – especially when it comes to your fertility.

In order to make a mature egg both naturally and for IVF, there is a delicate and complex interplay of reproductive hormones that need to peak and flow throughout the month. And unfortunately for those with a sweet tooth, sugar is a major hormone disruptor and affects blood sugar balance, having a negative impact on this process.


What’s the evidence?

Some studies show that a lower intake of carbohydrates have links to better IVF success. It is known that eggs and embryos do not thrive in a high glucose environment.

In a study presented at the American Society of Reproductive Medicine (ASRM) meeting last year, IVF patients who switched to a low-carbohydrate, high-protein diet and then underwent another cycle increased their blastocyst formation rate from 19% to 45% and their clinical pregnancy rate from 17% to 83%.

Even non-IVF patients with polycystic ovarian syndrome have improved pregnancy rates after making this lifestyle change, the study’s author Dr. Russell noted.

Sharon Phelan, MD, from the University of New Mexico in Albuquerque said: “Although the blood glucose is not high enough to be in the diabetic range, it is enough to be toxic to the developing blastocyst.”


How does sugar affect fertility?


The term blood sugar relates to the amount of glucose in your blood stream at any one time – which in turn affects your energy levels.

An unhealthy diet (one that is high in refined carbohydrates – ie sugars – and saturated fats) leads to blood-sugar imbalance (manifesting as peaks and troughs of energy throughout the day), which in turn has a negative impact on the health of your reproductive system. First, low blood sugar (which will make you feel lethargic), stimulates the body’s release of stress hormones (adrenaline and cortisol).

Continued release of stress hormones alters the way in which your body responds to progesterone – which is so important for the proper function of the menstrual cycle.

Second, high blood sugar (that sugar-high burst of energy), when frequent and sustained, causes the body to release the hormone insulin, which aims to get sugar levels under control.

The trouble is that if  we have too much insulin in our system too frequently, the insulin receptors in the body (some of  which are on the ovaries) begin to desensitise, creating a condition called insulin resistance. This is a major risk factor for PCOS and may even directly cause damage to the woman’s eggs.

Sugar is empty calories which causes weight gain, which converts to fat and ages sperm and egg cells.

And there is more: sugar is empty calories which causes weight gain, which converts to fat and ages sperm and egg cells.

So keeping blood sugar under control is essential for optimising the chances of pregnancy, whether through IVF or naturally. Optimum nutrition provides a steady supply of blood sugar throughout  the day, in order to ensure stable energy levels and stable metabolic processes.

What can you eat?

All this said, I passionately believe that that couples who want to make a baby need to have treats. Who could live without bread, chocolate and sweet treats? Not me.

If you crave chocolate and sweets, I don’t believe that the IVF diet should be about complete denial. So, rather than thinking you must cut out all sweet foods, try to think about how you satisfy your need  from something sweet. Highly refined white sugar (in cakes, chocolate, biscuits, sweets and so on) has  been stripped of all the natural moderators in raw sugar – the nutrients that make the sugar less  damaging to the body. So, try to get your sugar fix from naturally sweet sources like:

Dried fruits

Dates, figs or apricots make wonderful, sweetening additions to stews and desserts; if you want a sweet snack, try a few pieces of dried mango rather than a chocolate bar. Organic maple syrup can not only make a healthier alternative to white sugar, but also contains the  nutrients zinc and manganese.



Honey is higher in calories, gram for gram, than refined sugar, but it has healthier components, including B-vitamins – a teaspoon drizzled over granola for breakfast, or used to sweeten desserts, is preferable to refined sugar.


A low-calorie natural sweetener (occurring in certain fruits and vegetables, including  strawberries and cauliflower) that can be extracted from its sources and used in baking and in coffee and tea as an alternative to refined sugar. It does have a laxative effect, though – so use it in moderation.

If you usually have sugar in your tea or coffee (bearing in mind you should minimise your intake of caffeine-containing drinks while you’re trying for a baby anyway), don’t be tempted to reach for artificial sweeteners, which are often made using some chemical nasties that can upset your body’s systems. Try instead to adjust your palate, gradually reducing the amount of sugar you use until you’re used to drinking coffee and tea without it.

MORE: 8 diet tips to boost your fertility

MORE: 10 foods that increase fertility


Zita West is leading London fertility expert. For recipes and meals that contain just the right amounts of complex carbohydrate and slow-release energy foods to keep your blood sugars stable and encourage optimum fertility, Zita West’s new book The IVF Diet: The plan to support IVF treatment and help couples conceive is out now from Amazon


Like this article? Sign up to our newsletter to get more articles like this delivered straight to your inbox.

More Healthista Content