My practice aims to enhance natural fertility by way of achieving metabolic health. A good metabolism is a foundation for youthful hormone levels, fertility, the basis for the prevention of pregnancy complications and it primes the health of the developing foetus. Anyone trying to become pregnant should aim to optimize body composition and enjoy the enhanced output of energy as part of their pre-conception care, on-going pregnancy and post-partum health. We advocate and support those who want to lose weight as one of the most important parts of preconception care. It is actually THE most important factor determining the reproductive success rate whether you are attempting natural conception or considering assisted reproduction.
The main obstacle to pregnancy
Weighing too much or too little can interrupt normal menstrual cycles, affect ovulation, or stop it altogether. Excess weight lowers the odds that IVF or other assisted reproductive technologies will succeed. It increases the chances of miscarriage, puts a mother at risk during pregnancy of developing high blood pressure (preeclampsia) or gestational diabetes and elevates her chances of needing a Caesarean section.
Weight Affects Fertility in Men, Too
My heart sinks whenever I see a pot-bellied male partner with obvious signs of metabolic disorders. Excessive alcohol consumption, smoking, stress – and even the type of underpants– can all affect the quality of male sperm but one of the biggest factors affecting sperm quality is body composition, ie obesity. In many countries, while rates of obesity have been increasing, male fertility has been declining.
Excess weight can lower testosterone levels, can oestrogenize men by increased aromatase activity, ie transforming testosterone to oestrogen, and it hinders the production of motile sperm cells which should be produced in abundant testosterone. Studies in both men and mice show that sperm from overweight males are less motile, are less likely to fertilise an egg and are less likely to result in a healthy birth. A man’s weight directly and indirectly influences many aspects of general health as well as his fertility and reproductive function.
Fat is alive! – another hormonal organ, a factory of inflammation
Long thought of as a static, passive mass, body fat is emerging as an active and complex tissue. Like the testicles or pancreas, adipose tissue generates a variety of hormones that influence appetite, activity, weight, and reproduction. The exquisite line of communication between the reproductive system and energy stores exist and there are a host of hormones providing feedback between the two that help determine fertility.
Adiponectin is the most abundant protein made by fat cells. It helps stimulate fat-burning processes, makes cells more sensitive to insulin and may enhance ovulation. The more weight you gain, though, the less adiponectin your fat cells make. This drop-off can contribute to insulin resistance and interfere with ovulation. It also elevates leptin and other hormones that disrupt ovulation. Extra body fat boosts levels of interleukin-6 and other cell-signalling molecules that interfere with the ability of a fertilized egg to implant itself in the lining of the uterus.
The fat that accumulates around the waist and chest causing central obesity is particularly dangerous, posing more of a health problem than fat around the hips and thighs. It has been linked with metabolic disarrays such as high blood pressure, high blood sugar, and heart disease. Belly fat, especially the visceral fat that surrounds the organs in the gut, secretes molecules that fire up inflammation throughout the body. In addition to promoting heart disease and diabetes, this burden of inflammation can also muffle ovulation.
Although BMI is a standard measure, I personally prefer looking at waist circumference (waist to hip ratio) as the most important indicator of overall health. Many people make the mistake of losing water or muscle mass with an outdated ‘eat less, exercise more’ approach.
A body composition analysis, which we undertake in the clinic, tracking fat and muscle percentage is useful for monitoring progress.
Enter Fertility Zone
As previously mentioned there is a strong connection between weight and fertility. Women with the lowest and highest BMIs are more likely to have trouble with ovulatory infertility than women in the middle. Infertility is least common among women with BMIs of 20 to 24, with an ideal around 21. We call the range of BMIs from 20 to 24 the fertility zone. Having a weight in that range seems to optimal for getting pregnant.
Relatively small changes are often enough to have the desired effects of healthy ovulation and improved fertility.
If you are too lean, gaining five or ten pounds can sometimes be enough to restart ovulation and menstrual periods. If you are overweight, losing 5 per cent to 10 per cent of your current weight is often enough to improve ovulation. Numerous studies have shown that losing that amount can jump-start ovulation even when that loss doesn’t get them into the healthy weight range.
Among women with polycystic ovary syndrome (PCOS), this amount of weight loss can not only restore ovulation and menstruation but can also clear the skin and curb excess facial and body hair. These improvements are probably the result of better sensitivity to insulin and a decrease in the amount of male hormones in circulation.
- We don’t do calorie counting.
- We don’t encourage weight loss through exercise.
Over the years I’ve helped close to 1000 people, young and old, men and women to lose weight successfully. I outlined our approach in a separate article here.
As you progress, your tissues will slowly but surely become more sensitive to insulin. As your body fat shrinks, so will the flow of ovulation-interfering hormones that streams into the bloodstream.
My one piece of advice: Fat doesn’t make you fat but beware of liquid calories!!!