Energy Requirements Around the Phases of the Menstrual Cycle
By Flora Crichton BA HONS, DipION, MBANT, CNHC
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Understanding the phases of a menstrual cycle is empowering for a woman. It certainly has benefited me hugely, understanding why I might feel a certain way, or why I might be hungrier at a certain point in my cycle. As women, we may feel pressure to look a certain way, to diet or even eat ‘low carb.’ I felt this pressure growing up too, but since working as a Nutritionist, I have learnt these diets can wreak havoc on a woman’s period and fertility. The female body is complex, and requires a balance of protein, fat, carbohydrates and fibre, to function optimally and feel its best mentally.
Before I delve into the energy requirements for a woman’s cycle, I will describe the main phases. A woman's menstrual cycle starts on day 1 of her period, and lasts all the way through until her next period. After her period, the follicular phase begins, lasting around 10-14 days, until ovulation. Oestrogen, a proliferative hormone, rises here, stimulating the uterus lining to grow and thicken. Ovulation typically occurs around day 14 (it does vary), when the egg is released from the ovaries. Next follows her luteal phase, where progesterone hormone rises. Enough progesterone is vital to maintain a healthy uterus lining, but also to maintain a positive mood and reduce symptoms of PMS. This phase lasts around 14 days, and then your period (menstrual phase) arrives.
The follicular phase
As oestrogen rises in the follicular phase, it triggers serotonin release, so a woman typically feels quite positive at this stage, productive and sociable (this isn’t always the case, if your oestrogen levels are low). Your appetite won’t be as high as your luteal phase. Lighter foods and high fibre foods can be beneficial, to support our digestive health and optimise bowel movements. Since oestrogen levels are increasing, we need to be effectively removing oestrogen from the body, once it’s been used, via a bowel movement or the urine. Otherwise, oestrogen can recirculate back into the body. This can contribute to heavy, painful periods. High fibre foods include berries, apples, avocado, dark green leafy veg, sweet potato and brown rice.
The luteal phase
The luteal phase takes place after ovulation and runs up to the bleed. As progesterone hormone rises, it raises our metabolic rate. Progesterone signals for muscle tissue (amino acids) to be broken down, to be used as fuel to build the uterus lining. This process also requires glucose (carbohydrates). We need to take in about 150 calories more per day here. This includes a 12% increase in protein needs, and may explain the cravings women experience premenstrually. By having a portion of protein and complex carbohydrates at main meals (and snacks if we are hungry), we can support less cravings. There is no need to feel guilty for feeling hungrier here; our body is burning more fuel.
Women shouldn’t cut carbohydrates from the diet, as this may prevent ovulation, reduce progesterone production and inevitably worsen PMS. I believe cutting carbs or intermittent fasting is a disservice to menstruating women, because it will increase her cortisol (stress hormone) levels, compromising her hormone production and fertility. Consuming a starchy carb every 3-4 hours in the run up to a woman’s period, may alleviate her symptoms of PMS. I am referring to complex carbohydrates, such as grains, fruit or starchy vegetables e.g. carrots, potatoes, sweet potatoes and beetroot. These are high in fibre and contain slow releasing carbohydrate, giving you consistent energy levels. Most women also need more protein across the entire menstrual cycle, paying specific attention in the week before her period starts. A diversity of protein sources should be included; tofu, beans, lentils, chickpeas, tempeh, nuts, tahini, seeds, chia, flax, protein powders, fish, eggs, cheese and meat.
I supplement with 200-300mg of magnesium glycinate before bed, during my luteal phase, because the body uses more magnesium when building the uterus lining. Magnesium also stabilises our blood sugar, which is important at this stage, when blood sugar is more sensitive. Magnesium glycinate may relieve symptoms of migraine, PMS, PMDD and peri-menopause. The glycine in magnesium glycinate also calms the nervous system and promotes sleep. During the 3-5 days before your period, you are at your most inflamed, with a compromised immune system. Relax exercise here, because cardio & HIIT will increase cortisol (stress hormone) and increase inflammation, adding to the inflammatory burden. This includes any type of exercise where you feel like you are pushing yourself hard. Consider yoga, walking or swimming..
The menstrual phase
During your menstrual phase, you are bleeding. Since the body is shedding a uterus lining, this is considered an inflammatory time. Think about including warming, cooked foods, such as soups & stews, full of nourishing vegetables, beans and/or animal protein. Herbs and spices have a powerful anti-inflammatory effect on the body. In terms of exercise, if you don’t suffer from heavy bleeding or painful cramps, you can and definitely should exercise during your period. Perhaps strength training, that is lower in terms of weight, with longer rests. Personally, if I work out during the first 3-4 days of my period, I feel exhausted and low in mood coming out of my period. Whereas, if I stick to walking or gentle yoga, I feel much brighter coming out of my period. If you are working to get your periods back into a good place, rest is probably preferred.
Omega 3 fish oil can be an important supplement for any menstruating woman, particularly in the run up to her period, as the body is more inflamed. The body is inflamed, because we get a surge in something called prostaglandins, inflammatory immune chemicals. Prostaglandins trigger muscles in the uterus to contract, to help expel the uterus lining, as our period. Increasing your dose of omega 3’s to 2000 mg daily can be beneficial, for mood, bleed and reducing pain. Curcumin can also have an anti-inflammatory effect, and work to reduce the prostaglandins. Otherwise, I don’t typically recommend specific supplements, without testing a woman's hormones & genetics. When we understand where someone is genetically vulnerable, in terms of her hormone detoxification, we can go in with well placed supplements that benefit her individual physiology.
ABOUT THE AUTHOR:
Flora Crichton
Flora Crichton is a nutritionist specialising in period health. Flora studied Nutrition & Dietetics at The Endeavour College of Natural Health, Sydney, Australia. Then transferred back to the Institute of Optimum Nutrition, Richmond, to complete her studies. Flora’s chosen niche is menstrual health, due to her own personal journey.
Floras website: https://www.floracrichtonnutrition.com/
Floras Instagram: https://www.instagram.com/flora_crichton_nutrition/?hl=en