Extreme dieting reduces IVF success

Research clearly shows that fasting or ‘starving’ oneself increases production of the stress hormone, cortisol, in the body, she said.

“Also, intense dieting can be physically stressful on the body. The main raw material needed to make this stress hormone just happens to be the same raw material you need to make sex hormones, oestrogen and progesterone.

"Simply put, making too much stress hormone means you may not have enough raw material left over to make sex hormones,” she says.

IVF, she added, was a stressful time when a woman should take the time to nourish her body and take care of herself.

“Weight loss should not be synonymous with misery, deprivation and hunger. We recommend eating three small meals per day and two healthy snacks.

"Each meal or snack should contain good-quality protein or healthy fats to keep you fuller for longer,” she said.

Wright is a director and senior nutritionist at Glenville Nutrition, which specialises in nutritional support for male and female fertility and women’s health.

“Coupled with this pattern of eating, we recommend following a Mediterranean-style diet.

"It has proven benefits for fertility in other ways such as increased antioxidants, minerals and omega-3, which can benefit egg quality and sperm quality.

“This means plenty of fruit and vegetables, and healthy fats such as nuts, seeds, hummus and oily fish.

"Focus on eating a wide range of healthy foods regularly throughout the day, helping to ensure you are getting the nutrients you need.”

A typical day might look like this

Breakfast: 2 boiled eggs, tomato with one slice of wholegrain toast.

Mid-morning snack: Carrot or pepper sticks with 1 tablespoon hummus.

Lunch: Wholegrain chicken wrap with mixed salad, 1 apple.

Mid-afternoon: 2 rice cakes with peanut butter and half a banana sliced.

Dinner: Baked salmon with oven roast vegetables and small baked potato.

Glenville Nutrition also recommends gentle to moderate exercise: “Using a variation of resistance exercise and cardiovascular exercise will help to reduce body fat more efficiently.”

Of course, difficulty in conceiving is not always about how much a woman weighs.

Studies have shown that overweight men have lower levels of testosterone and sperm quality issues.

“Working as a team to eat healthily and lose weight when necessary can make a significant difference to your chances of having a healthy baby,” Wright said.

Nutrition also has a big role to play in improving sperm health.

A couple can increase their chances of having a family if both parties start to improve their diet about three months before trying to conceive.

For the man, that means plenty of antioxidants, which are found in fruit and vegetables, nuts and seeds.

“We recommend including two portions of fruit and five portions of vegetables per day to boost your antioxidant levels,” Wright says.

“Different-coloured fruits and vegetables contain different antioxidants, so it is very important to ‘eat a rainbow’. Including a variety of nuts and seeds daily is a good way to obtain mineral-based antioxidants such as zinc and selenium.”

It’s also important to limit any sources of damage, for instance, exposure to over-hot baths, heated car seats or mobile phones in the pocket. Supplements can be a good idea, too, but not to excess.

It’s also worth doing a DNA fragmentation test to measure sperm quality and assess the likelihood of natural conception.

DNA inside the sperm is vulnerable and there have been recommendations to include this test as a front-line test, and not just for those who have failed IVF cycles.

If there is DNA damage , the good news is that it can be repaired.

“Unless there is another underlying condition, in a lot of cases, nutrition and lifestyle changes are very successful at reducing DNA fragmentation and allowing couples go on to achieve their dream of having a baby,” Wright said.