Energy Metabolism & Fertility

Energy Metabolism & Fertility
Our metabolic health is crucial for fertility, and our declining fertility rate is running parallel to our metabolic health crisis.


I was born 6 weeks premature and over 9lb 6oz. I was unusually huge. Filling up the incubator like a Christmas turkey squashed into a Crockpot. By far the biggest prem baby anyone at Northampton General had seen for a while. I’ve proudly proclaimed that nugget of info anytime anyone has had a large baby, or premature baby, or any baby really.
What I didn't know and neither did my mum was that a baby with fetal macrosomia (literally, “big body”), defined as being born greater than 8 pounds, 13 ounces—was a fairly robust indicator of brewing metabolic disease, for both mother and child. Insulin is an anabolic (pro-growth) hormone, after all, and just like it promotes growth of cancers and fat, it grows babies too. 

Although I haven't got any data to prove it, I imagine my mum had insulin resistance during that pregnancy. She later had rising blood sugar, creeping cholesterol levels, leading to diabetes and ultimately passing away prematurely from ill health directly associated with metabolic dysfunction.

There were no practitioners to make the links between my mum’s various symptoms and extra-large babies? No one to educate and empower her to understand the potential root cause and what to do about it? Instead an endless list of prescriptions and without advised changes to her diet or lifestyle. But that was the 80s.

Disrupting Factors of Modern Life

Back to the present day. One of the main reasons our ability to reproduce is under siege is because of our metabolism – the engine that powers life – is being attacked. The malfunctioning of our reproduction is tied to underlying energy dysregulation in our cells, caused by the many factors of our industrialised modern living that are disrupting our ability to metabolise food to energy properly (factors ranging from chronic overconsumption of refined sugars and over processed foods to the metabolism-disrupting chemicals in so many of our products like food storage containers, furniture, makeup, and cleaning supplies).

One of the main reasons our ability to reproduce is under siege is because of our metabolism  – the engine that powers life – is being attacked.  


It is hard to ignore the recent studies showing our growing fertility issues are closely linked to the rise we are seeing in metabolic dysfunction. And It’s not just women, from 1973 to 2011, sperm count has dropped by more than 50 percent, a rate that we are seeing increasing and speeding up. Numerous studies show that metabolic syndrome is a root cause of male infertility. It is associated with lower testosterone levels, impaired spermatogenesis (sperm cell development), lower sperm concentration and motility, and increased damage to sperm DNA.

Risk of Miscarriage

Our metabolic health is crucial for fertility, and our declining fertility rate is running parallel to our metabolic health crisis. It’s worth noting that even when conception occurs, there’s still the risk of miscarriage, which can also be linked to metabolic dysfunction.


Cases of miscarriage have gone up 10 percent over the past decade (increasing at about 1% per year). Studies show metabolic dysfunction is associated with placental dysfunction and contributes to this increased rate. But since metabolic dysfunction can compromise sperm DNA integrity, metabolic health matters well before conception. In one study that compared semen characteristics of men undergoing assisted reproduction, those with diabetes had higher miscarriage rates than those without the condition.


Our metabolic health is crucial for fertility, and our declining fertility rate is running parallel to our metabolic health crisis.

More work needs to be done to promote metabolically healthy bodies, which can be achieved by making everyday lifestyle choices around diet, sleep, anxiety and stress management and exercise. It also involves our micronutrient levels and even our exposure to sunlight which is being affected by so many people currently working from home and not spending as much time outside compared to pre-pandemic levels.

The Link with Environmental Toxins

Environmental toxins also show a clear link between metabolic dysfunction, hormone disorders and infertility. At Naître we have been discussing these a lot with their link to the accelerating decline in sperm counts but it’s also worth stressing the impact they are also having on Female infertility. These toxins are largely unregulated industrial chemicals in everything from our mattresses to our plastic bottles to our deodorant—which can directly hurt our metabolic processes and our reproductive organs.


4 things you can do today to support metabolic health:

  • Eat more unprocessed, organic, non-starchy foods, like fruits, vegetables, nuts, seeds, beans, legumes, spices, and thoughtfully sourced animal products.
  • Switch to nontoxic home and personal care products. 
  • Minimize high fructose corn syrup (which sneaks into a lot of food) and added sugar from your drinks and foods.
  • Walk for a few minutes after you eat a meal or snack. Not only is his good for stabilising blood sugar but also topping up Vitamin D


When it comes to the micronutrient level, there’s 4 key vitamins that support metabolically healthy bodies: 


B Vitamins

The B vitamins play many fundamental roles in energy metabolism in the body and are essential in metabolising protein, fats and carbohydrates. 
The B vitamins include:
  • B-12
  • biotin
  • folate
  • B-6
  • pantothenic acid or B-5
  • niacin or B-3
  • riboflavin or B-2
  • thiamine or B-1

Deficiency in one of the B vitamins can affect other B vitamins, which can disrupt your metabolism.


Vitamin D

Two studies looked at vitamin D and weight in older women and children. Both found those participants with more fat had lower vitamin D levels than those with less fat.

Researchers are currently unsure about whether low vitamin D contributes to obesity or vice versa. Diet, blood sugar control, and time spent outdoors may all play a role in a person’s weight.

Research suggests that vitamin D may help control blood sugar and improve insulin resistance in people with diabetes.

Unlike other essential vitamins, people can get vitamin D from sunlight. Safe exposure to the sun is the fastest way to top up vitamin D.

If a person is overweight or has metabolic dysfunction, vitamin supplementation alone may not improve it. Weight loss has to come from lifestyle changes as well.

Nevertheless, a study in 2016 found that postmenopausal women with type 2 diabetes, eating vitamin D-fortified yoghurt, improved their blood sugar levels and reduced inflammation. They also experience reduced waist size.
An older study found that taking calcium with added vitamin D together slightly reduced the risk of weight gain and metabolic dysfunction in postmenopausal women.



Following on from the above, emerging research further suggests calcium may be vital to a healthy metabolism and blood sugar control, as well as healthy bones.

Some research from 2010 suggests that higher calcium intake combined with vitamin D can assist diet-related weight loss.

An older study in 2007 found that a diet high in dairy calcium enhanced weight loss in people with type 2 diabetes.

However, more recent research is needed to determine whether this is an effective strategy for improving fertility through improved metabolic function but it seems a natural place to start.

While calcium supplements are available, it is best for people to get enough calcium from food sources first.


In summary we are beginning to understand more about the link between a healthy metabolism and optimal reproductive health. Will optimising your mitochondrial function, insulin sensitivity, and blood sugar levels guarantee perfect fertility and pregnancy outcomes? Absolutely not. But it is a readily modifiable and largely ignored factor under our control, supported by research. It's an area of our health we need to take seriously when trying to conceive.