Fertility is definitely a weighty matter.

Being underweight or overweight can affect falling pregnant and so, it’s a good thing for both would-be parents to manage their weight at a healthy level.

And it’s much better to do that before trying to conceive.

Find out why right here, plus ways to help you manage weight.

This is not about body image or conforming to someone else’s/society’s crazy standards. It’s simply about health and hormones.


Hormones and Weight

Weight can influence hormones and so it’s important for women to consider when they want a baby.

Hormones need to be balanced for a regular, healthy menstrual cycle and releasing a healthy egg at ovulation.

If we’re either overweight or underweight, there is a risk that hormones are imbalanced and we start to notice signs, like cycle and fertility issues.


Being Overweight and Fertility

Some studies show that clinically overweight women are more likely to suffer fertility challenges.   Generally, the more overweight, the higher risk of problems.

The key reason is that overweight women tend to have more fat cells, than women who are not classed as overweight.

Our fat cells produce oestrogen.  I know that sounds weird, but fat cells do produce oestrogen, as well as our ovaries.

Because fat cells produce oestrogen, overweight women are at higher risk of “oestrogen dominance”. Oestrogen dominance simply means too much oestrogen in relation to progesterone. Oestrogen dominance can affect periods, ovulation and fertility.

Other common signs of too much oestrogen/ not enough progesterone include:-

  • Bloating
  • Sore breasts
  • Hormonal migraines and other headaches
  • Tiredness
  • Chilly hands and feet
  • Hair loss
  • Weight gain and slow metabolism
  • Sleeplessness
  • Low sex drive
  • Period problems
  • Thyroid issues
  • Endometriosis
  • Mood swings, irritability and depression
  • Infertility and miscarriage
  • Fibroids
  • PMS
  • Brain fog and memory issues.


Some studies also show that being overweight can impact the success of fertility treatment.  That’s why clinics and doctors sometimes ask overweight women to reduce their Body Mass Index (BMI) before fertility treatment starts. It’s believed it increases the chances of success.


Being Underweight and Fertility

Being underweight can also be an issue when trying to conceive.

That’s because underweight women tend to have a lower percentage body fat.

We need a certain amount of body fat for hormone balance and regular ovulation. When we’re underweight, our bodies “think” there are not enough fat stores for pregnancy, so we have risk issues falling pregnant and higher risk of miscarriage.

It’s not only the underweight who should watch out – we can be average or above average weight, but still have low body fat.

Take for example, female athletes or other women who exercise hard. Their low body fat and high muscle percentage can cause their periods to become irregular or even stop altogether.

BMI is one measure of weight and health.  It doesn’t show us the fat/muscle make-up of our bodies. We need a different piece of kit for that.  Many gyms have machines to measure fat/muscle or you could ask your doctor.

Accepted wisdom is that underweight is BMI lower than 20, most often quoted as under 18.5 Normal is 20-25. Overweight is 25-30. Obese is 30-40 and morbidly obese is over 40.


So what can we do if we’re under or overweight and trying for a baby?

Here are some tips :-


Tips for Managing Weight

It’s best not to go on a weight loss diet when you’re trying to conceive.

It’s better to lose weight first and then try for a baby.

Slimming diets – especially really strict ones – can cause periods to become erratic and ovulation to stop, because hormone levels drop.

This is usually temporary.

Reaching and maintaining a healthy weight and eating healthily should rebalance any issues in time. 

Wait until 3-4 months AFTER losing weight to start trying for a baby, if you can.

I suggest this as a precaution. Sometimes nutrient levels – including all the fertility fuelling nutrients –  can be low after a weight loss diet.

It’s good to make sure you boost nutrient levels if you’ve been on a really restrictive diet.

I use hair mineral tests from a Laboratory to help couples identify any deficiencies. Then we can work out what foods and supplements they may need.


Avoid fad diets.

Again, you risk robbing your body of nutrients, including the ones needed for fertility and healthy pregnancy and baby.

It’s best to lose gradually weight through a healthy, varied and balance diet.

And that includes healthy fats.

It doesn’t include “diet” or lite products because they can be jam packed with health and hormone harming chemicals and sugar.

The basics of a fertility friendly diet will serve you well to lose weight.

1-2lbs a week is a steady, healthy and great weight loss.

The aim is to lose weight to become a healthy weight for fertility, not slim as much as you possibly can. Losing a small amount of weight can make a difference to health and fertility.


Don’t start binge eating junk food to gain weight.

Please don’t start binge eating pies, shovelling in chocolate or snarfing takeaways!

They are NOT fertility-fuelling foods. No way.

Instead, eat more nutritious, calorie-dense foods – nuts and seeds, avocado, eggs, brown rice, oily fish and healthy fats and oils.  Increase your number of healthy snacks as well.


CROWD IN healthy foods to lose weight.

Losing or gaining weight is not always easy and it can sometimes seem daunting.

Let’s start with a simple idea – crowding in what you do want.  To crowd out what you don’t want.

So if – for example – you’re trying to cut down on sugar. Think crowding in more protein and soon you’ll be eating more protein, feel fuller and be eating less sugar.

Give it a go and see how it works for you.


Check out your partner’s (guy’s) weight.

Being overweight can affect male fertility. Being overweight has been linked to poor sperm quantity and quality.

One of my mantras is it takes two to tango and two to make a baby. Both women and men should tackle weight issues as part of preconception care.


Weight can affect chances of getting pregnant – that’s women and men.  Of course, it doesn’t always.

It’s always a case of giving yourself the best chance you can of natural conception or IVF success. And a healthy pregnancy and happy, bouncing baby, through sound diet and lifestyle choices.

It’s about taking control of the fertility factors that you can influence, including weight.

If you’d like support to lose or gain weight in a healthy way OR you would like to work with us and implement a fertility -friendly diet, get in touch.

We love to hear from you.