As the saying goes “men are from Mars, and women are from Venus.” So should we eat a different diet? It’s not that simple, but there are some valid reasons why specific diets have different gender outcomes. Body image and social pressure affect both men and women in terms of health and happiness. Unfortunately, many health and fitness professionals make the problem worse by encouraging unrealistic goals that can have detrimental impacts on the wellbeing of their clients. This is especially true for female clients as their hormones can be easily disrupted by the wrong diet or training methods.
Very low-carb diets, intermittent fasting, Ketosis, high-intensity interval training, and endless hours of aerobic training are prevalent in the fitness industry. They all have their place, and when used correctly, they can offer some incredible results. The problem occurs when these tools are abused, and the short term results push coaches and clients into the “more is better” mindset. Certain diets and training methods are designed to place stress on the body, which leads to adaptations and change. Long term exposure to these stressors can have negative impacts on our health and hormones. This overload of stress can cause menstruation issues and impact fertility if left unmanaged.
According to Monarch university, 90% of women experience at least one premenstrual syndrome (PMS) symptom most months, and about 50% of women get several symptoms each month [1]. PMS is a condition that affects a woman's emotions, physical health, and behaviour during certain days of the menstrual cycle. PMS can cause weight gain, fatigue, water retention, depression, anxiety, breast tenderness, constipation, diarrhoea, back pain, mood swings, acne flare-ups, changes in appetite, insomnia, brain fog, and headaches. Many conventional doctors will prescribe a contraceptive pill or even an antidepressant to alleviate the symptoms. These drugs come with side effects and don't address the cause of the PMS.
Science is not yet clear on the cause of PMS, but it appears to be an interaction between fluctuating sex hormones (such as estrogen and progesterone) and neurotransmitters (such as serotonin, dopamine, GABA and glutamate) [2]. Addressing sex hormone imbalances between estrogen and progesterone can often improve or even eliminate PMS symptoms. Severe PMS symptoms can be evidence of significant hormone imbalances and can lead to autoimmune diseases. Ignoring the signs and continuing to follow the same lifestyle behaviours can cause irreversible health problems. As personal trainers and coaches, we should be asking our female clients about their menstruation cycle as physical exercise can potentially have negative effects.
You might be thinking this is some pretty heavy shit for personal trainers and coaches to understand, but hormonal balance is critical to a woman’s health and reproductive system. Lifestyle factors such as diet, exercise, stress, rest and recovery, and social connection have a key role to play in women’s health. As health and fitness professionals we must be mindful that lifestyle factors, such as exercise and diet, can have negtive health impacts if not managed correctly.
Polycystic ovarian syndrome (PCOS), irregular or absent menstrual cycle (amenorrhea), insulin resistance (diabetes), elevated testosterone, inflammation, digestive issues, acne, excessive hair growth, weight gain, and infertility are just some of the health issues women can experience when their hormones are out of balance. Is your client willing to sacrifice their health for a certain body image?
Side note: Amenorrhea is associate with an increased risk of osteoporosis. Strength training has been shown to improve bone density, but other lifestyle factors have a key role to play.
The cause of hormonal imbalances is still not fully understood, but inadequate micro-nutrient intake, food sensitivities, high omega-6 to omega-3 ratios, poor quality sleep, weight gain, losing too much weight, low body fat percentage (<16%), etc. have been associated. Overtraining can also create hormone imbalances in women, as high levels of stress can affect hormonal production. The ovaries are controlled by the hypothalamic-pituitary-thyroid-gonad-adrenal axis, the HPTGA axis. High levels of stress, physical and mental, can impact the hypothalamus (brain), the pituitary gland (the body's 'master gland’), thyroid hormones (TSH, T3, T4, linked to both hypo- and hyperthyroidism), the gonad (ovaries), and adrenals (sex hormones and cortisol) and impact a huge array of hormones.
Side note: Thyroid health can play a significant role in fertility. Both hypo- and hyperthyroidism reduce the chances of conception and increase the risk of miscarriage. This is important because very-low-carb diets, such as ketosis, can have negative impacts on thyroid hormones.
Where am I going with all of this? How do diet and training impact a female's hormones? If a woman has PCOS, insulin resistance, or is clinically overweight (BMI>25.0), a low-carb diet under close supervision can be a valid approach. However, if a woman in not clinical overweight, a low-carb approach can cause health issues and make existing hormonal imbalances worse. How many personal trainers and coaches are talking to their female clients about the risks associated with long term low-carb diets? How many personal trainers and coaches are allowing their female clients to follow a low-carb, ketosis, or intermittent fasting diet? Are we promoting health and longevity, or are we promoting illness and disease?
What about exercise?
Excessive exercise in the form of high-intensity training or large volumes of training can cause serious hormonal imbalances in women. The "more is better" philosophy is not the case when it comes to sustainable health for women, and overtraining can lead to amenorrhea (very common in elite-level female athletes). Many elite-level athletes are willing to sacrifice their health so they can reach their performance goals, win competitions, and receive sponsorship money. The majority of our clients are not elite level athletes and there is no sponsorship or prize money attached to their goals.
You might be thinking, “if my female clients don’t have any health issues, do I need to worry?” If fertility, pregnancy and breastfeeding are a part of your client’s goals, then yes you do need to pay attention. Women need to make sure they are eating enough calories and enough nutrients to sustain their health and hormones.
Nutrient deficiencies
Nutrient deficiencies are very common in both men and women. According to the Australian Institute of Health and welfare:
Unbalanced nutrition is one of the three major risk factors for premature death in Australia, along with smoking and high alcohol consumption [4]
Less than 1 in 10 adults met the recommendations for daily vegetable consumption [3]
1 in 2 people aged 18 and over (49%) did not eat the recommended 2 serves of fruit, while over 9 in 10 (92%) did not eat the recommended 5–6 serves of vegetables (ABS 2018)
10% of adults consume sugar-sweetened drinks [3] which decrease mineral stores in the body
About 1/3 of Australia's energy is from discretionary food (foods and drinks not necessary to provide the nutrients with the human body needs) [3]
Is it any wonder we are sick, fat, and unhealthy? I didn’t even mention the alcohol statistics.
Back on topic, what nutrients are important for female clients who care about fertility, pregnancy, breastfeeding, and health?
Vitamin A, D and K2 - are all fat-soluble vitamins important for health and pregnancy. There is a nutrient synergy with these three vitamins - vitamin-A can be toxic when vitamins K2 and D are inadequate. It's important to have them all in balance and checked by your doctor.
B12 - as above. Low levels of B12 are also linked with infertility and developmental problems in babies. Over 62% of pregnant women are deficient in vitamin B12. The rates are even higher for vegans and long-term vegetarians[9]
A recent study noted that women referred for in-vitro fertilization were very likely to have inadequate B12 and folate levels. In fact, only 44% of the women had adequate B12 levels and only 12% had optimal folate levels [11].
When looking at embryo quality in IVF, researchers find that higher B12 correlates with better embryos. They also find that increased folate in follicles significantly increases the chance of pregnancy. [12]
Biotin - deficiency in biotin are rare. Low biotin can increase the chance of having children with birth defects. [16]
Choline - Low intakes are linked to neural tube defects [5]. Choline also plays important roles in modulating gene expression, cell membrane signalling, lipid transport and metabolism. When a diet is deficient in folate and b-vitamins the need for dietary choline rises [6].
Folate (not folic acid) - necessary for the production of new DNA and fetal cell division, therefore important for fertility and pregnancy [11]
A recent study investigated the role that folate plays in pregnancy. The study looked at women undergoing IVF, dividing the participants into three groups (low, medium, and high) based on folate levels. The women with high folate levels had more than double the likelihood of pregnancy. [10].
Glycine - helps to balance the methionine in diets that are rich in animal products. High methionine intake increases the need for B vitamins like folate, choline, and B12. [17]
Iodine - deficiency is associated with an increased risk of mental retardation and even cretinism.
Iron - important for avoiding anemia, especially during pregnancy. Low levels of B12, vitamin-C, or folate deficiency can also cause iron deficiency [8]
Omega-3 (especially DHA) - health fats are vitally important during pregnancy as they are critical building blocks for the babies brain and retina [13,14,15]
Zinc - folate and zinc have a nutrient synergy and hence they have absorption dependency.
Pregnancy and breastfeeding
Following a calorie-restricted weight-loss diet or a low-carb diet is a VERY BAD IDEA during pregnancy and breastfeeding. It’s not the time to be focusing on weight loss as the mother has two mouths to feed. Gaining weight is a NORMAL AND HEALTHY part of pregnancy. Consuming enough calories is critical for the development of the baby and for the mother’s health. Low birth weight is associated with an astonishing number of health conditions later on in life.
Breastfeeding women need about 300-500 extra calories a day to promote healthy milk supply. A moderate carbohydrate (20-30% of calories) to high carbohydrate (30-50%) intake is recommended as breast milk is 39% carbohydrate, 54% fat, and 7% protein.
In part 2 of Women's Health: Diet, Training and Hormones we will talk about the importance of gut health, the impacts of stress, toxic stress, sleep fundamentals, cutting calories, carbohydrate intake, training to support menstrual cycle, fasting and weight loss.
REFERENCES:
Premenstrual Syndrome (PMS) and Premenstrual Dysphoric Disorder (PMDD)
Sex hormones affect neurotransmitters and shape the adult female brain during hormonal transition periods, Barth.C et al. 2015
Choline concentrations are lower in postnatal plasma of preterm infants than in cord plasma, Bernhard W et al. 2015
Choline: critical role during fetal development and dietary requirements in adults, Zeisel SH. 2006
CholineFact Sheet for Health Professionals, National Institute of Health
Vitamin deficiency anemia, Mayo Clinic
How prevalent is vitamin B(12) deficiency among vegetarians? Pawlak R et al, 2013
Homocysteine pathway and in vitro fertilization outcome, Paffoni A et al. 2018
Folate, homocysteine and selected vitamins and minerals status in infertile women, La Vecchia I et al. 2017
IVF outcomes are associated with biomarkers of the homocysteine pathway in monofollicular fluid, Boxmeer JC et al. 2009
Dietary omega 3 fatty acids and the developing brain, Innis SM. 2008
Omega-3 Fatty Acids and Pregnancy, Jaclyn M Coletta et al. 2010
Brain development suffers from lack of fish oil fatty acids, study finds University of California. 2015
Marginal biotin deficiency during normal pregnancy, Donald M Mock et al. 2002
Do High-Protein Diets Cause Kidney Disease and Cancer, Chris Kresser. 2019
The Iodine Deficiency Disorders, Creswell J Eastman et al. 2018