Blood sugar is one of the main root cause of hormone imbalance. Both high blood sugar and low blood sugar can cause hormone imbalances and disturbances in the menstrual cycle. High blood sugar and insulin resistance is common in many women and worsens with age, insulin resistance is the largest known contributing factor in women with PCOS (polycystic ovarian syndrome) (1) (Read my article on PCOS here) and also contributes to menstrual cycle disturbances and mood disturbances in perimenopause (2). Insulin resistance leads to excess production of testosterone which can lead to irregular cycles due to inconsistent absent ovulation as well as symptoms like weight gain, acne, thinning hair or unwanted body and facial hair.
On the other hand, when blood sugar drops too low it releases adrenalin into the system which is responsible for many of the low blood sugar symptoms including anxiety. Eventually, adrenaline spikes the hormone cortisol (the stress hormone). Cortisol and adrenalin send a message to the pituitary gland in the brain that there is “danger” or a “threat” and the brain responds by lowering sex hormone output while diverting energy to deal with more important bodily functions. Low blood sugar occurs from frequent consumption of refined sugars (cakes, sweets, soft drinks) because a very rapid and large rise in blood sugar is followed by a very sudden and severe drop in blood sugar (3). However low blood sugar is also caused by inadequate calorie intake (not eating enough) or waiting too long between meals. Low blood sugar is associated with nervous system dysregulation, anxiety or aggression (hangryiness) and generalised lower hormonal output leading to inadequate estrogen and progesterone production, longer cycles and even missing cycles (4).
When it comes to blood sugar regulation, how to eat is just as important as what to eat. When I used to work in dental (as a dental hygienist and kids dental therapist) I was constantly advising parents and their children prone to dental cavities, “it’s not about how much sugar you eat, it’s about how frequently you eat it.” This is the same for blood sugar balance. The body undergoes a series of chemical processes once food is consumed and if not allowed time to carry out its functions it will lead to digestive upset as well as blood sugar dysregulation. Correct eating and lifestyle habits are the basis of blood sugar regulation. Working on setting up correct habits around blood sugar management will not only help to correct hormone imbalances but will set up the body for lifelong success in helping to prevent chronic diseases like diabetes and heart disease.
Here are some proven lifestyles and eating habits known to help stabilise blood sugar levels
Limit refined sugars and processed refined carbohydrates: This spike blood glucose too high which is often followed by a rapid drop in blood glucose leading to overeating and excess cortisol production (3)(8).
Eat enough food: Many women do not eat enough to support stable blood sugar. Most women need 2000 calories a day for stable blood sugar levels and 200-300 calories more in the luteal and menstrual phases. Learning to eat enough (not too much and not too little) is crucial for blood sugar (17).
Limit saturated fat intake and lower consumptions of animal products: the results of numerous animal and human studies have consistently shown that saturated fat (found predominantly in animal products) is associated with insulin resistance, PCOS and type 2 diabetes. Saturated fat makes it more difficult for the liver and pancreas to process sugar well (6). Similarly, animal protein, red meat, in particular, has been found to increase insulin resistance and increase risk of developing type 2 diabetes (7)
Eat Breakfast: Eating breakfast preferably within 1-2 hours of waking is one of the best ways to reduce cortisol in the morning. After fasting all night, the body has entered “starvation” mode. This is when the liver has already used its stored up glycogen and the body must create energy from the breakdown of protein and fat as opposed to glucose. This is a highly stressful state for the body and requires a good amount of cortisol to get the job done. It is common practice for the evening dinner meal to be the largest meal of the day however, mornings are the time of day when our body is most able to use the glucose in our food effectively. Our bodies need energy in the morning to prep us for the activity of the day ahead. The body needs less food in the evenings when the body is prepping for sleep and be inactive for the night (9).
Do not snack between meals or graze throughout the day. Stick to three large balanced meals a day: Constantly eating throughout the day will spike blood sugar every time food is ingested, even if eating a very low carbohydrate meal (protein can also spike blood glucose). This means that insulin is constantly being released into the bloodstream to help move glucose out of the blood and into the cells. Elevating insulin too often can lead to insulin resistance and menstrual cycle disturbances as a consequence. Regular snacking and grazing also causes digestive distress as the gut needs sufficient time to process foods correctly. Note: meals need to be calorie sufficient in order to avoid snacking or blood sugar drops (10).
Always eat a good balance of protein fats and whole carbohydrates: Carbohydrates containing a good amount of fibre have been consistently shown to help prevent type 2 diabetes and improve insulin resistance, the addition of plant-based protein (found in all plant foods but most concentrated in legumes like beans and lentils and nuts and seeds) and healthy monounsaturated fats (found in avocado’s olive oil and macadamia oil) and polyunsaturated fats (found in most nuts and seeds and their oils) further helps to stabilise blood sugar and leads to a feeling of satiety of fullness (8).
Increase fibre intake: fibre helps drop the glycemic index of our foods and it helps to flush out excess estrogen and other hormones and toxins from the body which is important for most hormonal imbalances. Many studies have also shown high fibre diets to promote weight loss in PCOS and diabetes as well as regulate blood sugar and insulin levels. All plant-based foods contain some fibre but some are higher in fibre than others (13).
Do not eat the last meal after 8 pm at night or at least 3 hours before bedtime. The body generally becomes more insulin resistant as the day progresses. We have evidence suggesting that exactly the same meal has double the effect on blood glucose in the evening compared to the morning. The cut off appears to be 8 pm at night, after this time the body is preparing to sleep and has switched to conserving energy for the night ahead. Eating while the body is in conservation mode will cause the body to hold on to more glucose than needed and cause digestive upset. Fasting should occur overnight while sleeping and not during the day (11) (12) (15).
Do not drink anything besides water in between meals. Sugary drinks (even healthy ones) are the quickest way to spike blood sugar as they bypass digestion. Any drink besides water should be considered to be a meal and be paired with meals in eating windows (have other drinks about 15 minutes before or after main meals to not upset digestion)
Reduce emotional stress: cortisol releases more glucose into the bloodstream, it is what helps us deal without emotional stress (flight or fight response) over time this can lead to blood sugar dysregulation especially if it is chronic. There is evidence that stress alone can cause diabetes-like conditions even when insulin levels are healthy and diet is optimal (13).
Exercise smartly. Exercise tolerance varies between individuals and at different times of the month. While exercise is a great way to reduce blood sugar and move it into our muscles for energy (this is what we want) it can also lead to added stress on the body if exercise is done to the extreme. This is because exercise also releases cortisol in the bloodstream. High cortisol and insufficient calories to replenish energy lost during exercise are often associated with women that have lost their periods (hypothalamic amenorrhea) due to under eating, overexercising or both. Finding the right balance of exercise is crucial for blood sugar regulation (16).
As a side note, women who experience severe anxiety or trauma often have adrenal dysfunction (HPA axis dysregulation) and need to be much more mindful of avoiding blood sugar drops. Low blood sugar itself causes and exaggerates anxiety and exacerbates existing anxiety disorders. Chronically high cortisol from anxiety or trauma can cause blood sugar to rise and fall more rapidly while also depleting the liver of glycogen stores leading to a tendency towards blood sugar crashes. In this case a well-balanced breakfast within 1 hour of waking is absolutely crucial. It is also often it is necessary for women to eat every 3-4 hours and before bedtime to help keep blood sugar stable. This keeps cortisol a little steadier and can provide a biological advantage to help manage anxiety. This type of eating is used therapeutically by some professionals when dealing with anxiety and trauma disorders for a period of 2-3 years. As the nervous system regulates and anxiety improves eating often becomes less important. As always, it’s best to seek professional guidance.