The current buzz around intermittent fasting for women has linked it to everything from improved gut and heart health to a better menopause and even a longer life. So is it simply a new fad or could intermittent fasting during menopause be a very real and effective solution to menopausal weight gain and other symptoms like brain fog? Find out how it works and what it could do for you…
What is intermittent fasting?
Intermittent fasting (or IF) is quite simply fasting – or not eating – for a specific amount of time. You are basically switching between periods of fasting and eating as usual. Read on the learn about the best types of intermittent fasting for menopause which vary in length of fasting and calorie intake giving you some options to choose from.
Intermittent fasting for women
The health benefits for women of intermittent fasting still need to be studied more extensively but research has shown it not only has a beneficial effect on managing your weight but it could also lower the risk of many chronic diseases like heart disease. How does it do this? The theory is that fasting mildly traumatises cells in your body making them stronger and better able to protect you from ill health. This protective mechanism is known as autophagy.
These physiological changes caused by intermittent fasting could help reduce and/or improve many of the common symptoms and medical concerns experienced by women around the time of the perimenopause and menopause (typically around the ages of 45-55). A study published in the Journal of Mid-Life Health exploring the Role of Therapeutic Fasting in Women’s Health suggests it can help women to both lose and manage their weight; lead to better bone health and increased muscle mass; improve mental health and it has a positive effect on metabolic health (leading to more balanced levels of blood sugar, triglycerides, HDL ‘good’ cholesterol, blood pressure and abdominal fat) and it may even play a role in preventing some cancers. These are all common considerations and health issues for women at this transitional time of life and intermittent fasting is generally acknowledged to be a safe and effective.
What does fasting do for menopausal women?
The range of physiological reactions triggered by fasting also appear to impact positively on gut bacteria and the hormones that are responsible for insulin and glucose management in the body. Optimising insulin function should help keep your blood sugar levels in a healthy and normal range – protecting you from unhealthy high sugar spikes and lows (which can leave you tired and exacerbate brain fog) and potentially from developing type 2 diabetes.  Why this is important during perimenopause and menopause is that the hormonal fluctuations at this time can cause changes to your metabolism including potentially insulin resistance meaning you may have trouble processing sugar and refined carbohydrates. This can contribute to unwanted weight gain and the so-called Menopause belly.
The best types of fasting for women in menopause:
There are currently several popular variations of intermittent fasting (IF) including:
- Overnight fasting – this is probably the simplest method and involves a 12-hour period of fasting every day. For example, if you eat your final meal by 7pm and then resume eating again at 7am you have ‘fasted’ for 12 hours (although it probably doesn’t feel like it because you have probably been asleep for much of that time).
- Time-restricted eating – the 16:8 or 18.6 method – this is a form of daily fasting where you can only eat at certain times of the day. On the 16:8 you don’t eat for 16 hours but then eat your normal meals and snacks within an eight-hour period. Using the 18.6 plan you fast for 18 hours and then limit all the food you eat in the remaining six hours of the day.
- The 5:2 method – this involves having two days of the week where you consume only 500 calories (there are a range of 200 calorie and 300 calorie meal recipes online to give you inspiration but these are meals that need to be nutritionally dense and packed with protein and fibre to help keep you not just healthy but fuller and more satisfied for longer). For the other five days you eat a normal healthy balanced diet (for example, like a Mediterranean-inspired one. Link to Meno and Med Diet page).
- Alternate day fasting – is as its name suggests this involves fasting every other day. The most common version of this diet involves a “altered” fasting, where you can eat around 500 calories on fasting days.
How does Intermittent fasting work in practice?
Basically, by allowing you to pick a time window and setting the rules for when you eat. So, for example, many people find it easiest to confine their meals to eight hours of the day – say, from 9-5 – and then fast for the remainder. This works well for people who prefer an early dinner and then most of the time you spend ‘fasting’ you are probably in bed so it is unlikely to feel too much like you are being deprived of food. Outside of your designated eating window you drink just water or other non-calorific drinks like tea, coffee or herbal or fruit infusions/teas. Intermittent fasting is not about starving or deprivation – it’s about improving blood sugar balance and overall metabolic health. It should also give your GI tract a welcome rest from digestion and allow time for the beneficial bugs in your gut to flourish.
Fans of intermittent fasting are often evangelical about its benefits on their health and weight and say that they quickly get used to their new patterns of eating.
How can intermittent fasting help with menopause?
What we know, so far, about how IF can help menopausal women includes:
- Hormone changes. Concerns have been raised in the past as to whether intermittent fasting could negatively impact on female sex hormones (including potentially affecting a woman’s fertility). A recent study, however, published at the end of 2022 followed a group of pre and post-menopausal obese women over eight weeks on an intermittent fasting plan that involved eating during a four or six hour window. The women in the study lost between 3-4% cent of their baseline weight and experienced a drop in insulin resistance (when your body cannot use your insulin levels effectively and blood sugar levels can increase) but the researchers found that intermittent fasting did not change levels of female reproductive hormones. The study did reveal, however, that all the intermittent fasters showed a drop in the hormone dehydroepiandrosterone – or DHEA – and it has been suggested that since high DHEA has been linked to an increased breast cancer risk this could potentially reduce the risk for both pre-menopausal and post-menopausal women. (Figures from the NHS show that eight out of 10 cases of breast cancer happen in women over 50 and the average age of menopause in the UK is 51). The researchers are keen to point out these are preliminary findings and more research is needed, however.
- Losing weight and reducing belly fat – it probably won’t come as a huge surprise to learn that most people are trying intermittent fasting (IF) in order to lose weight – or that if you go without food for significant amounts of time you are likely to do exactly that. What is different with IF is that it improves hormone functions that appear to not only facilitate weight loss but also, significantly, keep it off – a seeming side effect of insulin levels dropping and human growth hormone (HGH) increasing. Reduced levels of insulin have been shown to help to improve fat burning: One study involving people doing alternate day fasting for eight weeks were found to have lost both weight and visceral belly fat and interestingly reported that they didn’t feel any hungrier than usual. Higher levels of HGH help to facilitate fat burning and build muscle. Short term fasting has also been shown to increase metabolic rate helping you to burn calories faster. According to a review of the scientific literature If can lead to weight loss of between 3-8% over 3-24 weeks. This is a significant amount to lose in a short space of time and has led experts to suggest IF could be a useful preventative tool in reducing the risk of not just becoming overweight or obese but also developing type 2 diabetes (something many women entering menopause are more at risk of due to their age, them putting on weight and potentially having higher blood pressure). The weight loss potential of IF is particularly pertinent for women going through the menopause as we know women put on an average of 5lbs at this time in their life and this can have a huge effect on their self-confidence as well as putting them at greater risk of certain health conditions.
- Improved gut health – we know that declining levels of oestrogen during perimenopause and menopause can impact on gut health. Recent data shows that women have a different microbiome to men and during perimenopause and menopause this delicate ecosystem of micro-organisms becomes less diverse which can impact negatively on your body and psychological health – including interfering with the production of some neurotransmitters like serotonin (the so-called feel-good hormone). The brain has a direct effect on the gut (often dubbed the second brain) and this is a bi-directional relationship (known as the gut-brain axis) – meaning an unhealthy or upset gut can lead to an upset and anxious mind. Increasing research suggests that literally giving your gut a bit of a break by fasting (ie. not eating to allow it a bit of space to recover from incessantly having to digest food can help to create a better balance of beneficial bugs) can improve the health of your gut microbiome. This, in turn, is linked to improvements in your mood and psychological health.
- Helps reduce inflammation in your body – studies show IF can reduce inflammation in the body, a key driver of many chronic diseases including heart disease. This is significant when we know that oestrogen acts as an anti-inflammatory, and diminishing levels of it during perimenopause and menopause are thought to trigger inflammation, potentially leading to symptoms like joint pain and possibly even neurodegenerative conditions in later life.
- May improve your heart health – Oestrogen has known heart-protective effects and perimenopausal and menopausal women experiencing declining levels of this hormone are at an increased risk of heart disease. It has been shown that regular fasting results in acute changes in biomarkers (molecules found in blood or other tissues that can detect or confirm a disease or condition) of metabolic and cardiovascular health. The long term implications of this are largely unknown and more research is needed to evaluate its role in potentially reducing the risk of metabolic disease (the medical term for high blood pressure, obesity and diabetes which put you at higher risk of heart disease and stroke)  but studies on animals show IF appears to improve numerous risk factors for heart disease including high blood pressure, cholesterol, triglycerides (a type of fat found in the blood) and markers of inflammation. Intermittent fasting is also likely to help you lose and/or manage your weight and this should also lower your risk of heart disease. 
- May improve your cognitive and mental health – the research into IF and brain health is largely in its infancy, but we do know fasting increases levels of a hormone called brain-derived neurotropic factor (BDNF). A deficiency of this has been linked to depression and a number of brain problems including issues with memory. There is also some evidence that intermittent fasting could improve cognitive health as we get older as well as reduce problems like anxiety and depression (these are symptoms which are reported by many women going through menopause). There is also some research to suggest that restricting calories can increase your ability to produce new brain cells, or neurons, and these could help improve some aspects of memory. This could be potentially beneficial for oestrogen-deficient women going through menopause who are having memory lapses or other cognitive problems.
Are there any downsides?
Overall, the evidence suggests intermittent fasting is not harmful to your physical or mental health. There are, however, some potential drawbacks including the fact that much of the evidence is based on animal studies and not human ones so we need to have more robust clinical studies – especially involving perimenopausal and menopausal women.
Some critics also point out it could lead to:
- Disordered patterns of eating – by setting up a cycle of binge and restrictive eating. This is particularly pertinent if you have, or have had, an eating disorder, including anorexia or bulimia.
- Nutritional deficiencies and dehydration – if you are eating healthily during your ‘eating window’ it is unlikely you will be lacking any nutrients but if you don’t plan your meals well or your bouts of fasting become too extreme this could potentially lead to you not getting the range of nutrients you need. The key when you do eat during your designated window is not to count calories but to make what you do eat count nutritionally. Avoid processed and sugary foods and refined carbohydrates (like white bread, white rice and pasta) and go for nutrient dense foods like fruit, vegetables, whole grains, pulses and healthy fats like extra virgin olive oil and those found naturally in oily fish, avocados, nuts and seeds. (You can find more advice and healthy recipe and snack ideas in Menopause and the Mediterranean diet). Also, try to keep yourself well hydrated with plenty of water or herbal teas. During the initial days of fasting your body releases large amounts of water and salt and if these are not replaced you can be at risk of dehydration so drink enough fluids.
- Leaving you hungry and ‘hangry’ – going without food for significant amounts of time can unsurprisingly leave you hungry and cranky. When we are hungry and our blood sugar drops we can become irritable, tired, potentially light-headed and find it difficult to concentrate (in short, symptoms of brain fog). When you feel like this you are also more likely to crave ‘quick fix’ sugary or processed foods which are likely to send your blood sugar levels rocketing. Also if your stomach is growling the temptation is to ‘fill up’ on coffee and diet cola to take away those hunger pangs but unless you go for decaffeinated varieties this could exacerbate perimenopause and menopause symptoms. As our Health & Her research reveals 44% of women report becoming more sensitive to the effects of caffeine as they headed towards menopause.
- It is not suitable for everyone. For example, if you have medication you are advised to take with food and/or if you work different shifts or irregular hours it can be difficult to make intermittent fasting work around this. Also it is not recommended if you are pregnant or you have known blood sugar problems.
How to intermittent fast during menopause
So how do you make it work in practice? Nutritionist Helen Roach says,’ My advice is to follow the 16.8 version of fasting as 1. it’s fairly easy to stick to and won’t interrupt your schedule and daily eating patterns too much 2. It’s less likely to make you feel extreme hunger and lead to cravings and 3. it’s more realistic as a long-term lifestyle habit (than, say, attempting to stick to a 5:2 one. I would also suggest that 12-hour overnight fasting might not be effective enough for women who are over 40.’
Here Helen Roach has prepared a sample day’s IF meal plan:
- 7 am – Peppermint tea
- 8 am – Black coffee
- 9 am – 2 egg spinach omelette
- 11:30 am – Natural unsweetened yoghurt, blueberries, chia seeds & walnuts
- 2pm – Salmon & roast chunky veg
- 4:30pm – Baked avocado with hummus and red onion
- Fast – 5 pm-9 am
NB: It is better to eat as early in the day as possible as insulin is more efficient before 3 pm. Eating closer to bedtime is not advised regardless of which intermittent fasting plan you choose to follow.
The IF takeaway
Intermittent fasting appears to offer a hopeful solution to menopausal weight gain and may reduce a range of other symptoms or conditions linked to the hormonal changes that can occur at this stage of life.
If you have any existing health conditions or are taking medication do check with your doctor before starting an intermittent fasting plan.
Sources and references