When Fasting Works for Women (and When It Doesn’t)

Fasting is everywhere right now, from podcasts to biohacking experts, and the science is quite astounding. With all this amazing research and stories of people thriving, it can be confusing when you don’t feel like that.

I truly believe fasting can serve you, but only when your body is in a place of balance. If not, that’s the time you need something softer like more nourishment, not restriction.

So, let’s talk about who it benefits, the impact on hormones, and the alternatives to intermittent fasting.

Does Intermittent Fasting Work for Women?

This question is appearing more than ever. Is it because women across the globe are feeling weak fasting, not seeing the results of their friends, husbands, or brothers?

The thing is, for men, fasting can be incredible for blood sugar control, focus and energy. They can happily train fasted and feel great after. However, we are women, and our physiology is totally different.

And here’s an interesting fact for you, up until 1995 the vast majority of health and nutrition studies were based only on men. Which means most of what we know about fasting is built on a physiology that doesn’t cycle monthly like ours does.

Men thrive on consistency, whereas our bodies are designed to ebb and flow. Oestrogen and progesterone influence metabolism, mood, appetite, and even how we process carbohydrates.

What supports one woman might completely stress another, that’s the nuance missing in the one size fits all fasting trend.

How Fasting Shapes Your Hormones

I do wish this was talked about more. Fasting can change levels of cortisol (our stress hormone), thyroid hormones, insulin, and sex hormones. For example. when cortisol rises too high, it can suppress thyroid function and increase cravings, thus, lesser results.

For some women, especially those with healthy adrenal function and balanced stress levels, fasting may bring focus and lightness. For others, it can tip the nervous system into overdrive, leading to poor sleep, anxious thoughts, irregular cycles, or stubborn weight gain. 

I’ve been there before, and I’ve learnt my body needs carbohydrates to function - but again, this is the beauty of the body and the difference in everyone’s physiology.

So yes, fasting can influence every hormone that shapes a woman’s rhythm. It’s not a case of good or bad, it’s all about context.

Why Did Intermittent Fasting Not Work for Me?

If you’ve tried fasting and found yourself drained, moody or craving sugar, just know you’re not alone. If you didn’t lose a pound (if that was your goal) or even gained weight, take a minute to understand how restriction can increase inflammation - one of the key drivers of visceral fat, the deep belly fat and inflammatory fat stored around organs.

Fro women, fat loss and hormonal balance happen when the body feels safe, and that safety comes from nourishment. Plus, your brain and liver need steady glucose to function and thrive, without it your energy, mood and metabolism all take a hit. 

Sometimes the very restriction meant to help us heal is what slows us down, and this could be why your intermittent fasting stopped working, or never got off to a start in the first place.

How to Intermittent Fast Over 40 (If You Choose To)

I wanted to touch on this as I see so much advice telling women in perimenopause and menopause to fast. I’ve met many women in their 40s doing 72 hour water fasts, but feeling awful!

An important note is as we move through these stages, oestrogen drops and inflammation rises,  that’s why aggressive fasting or restrictive diets can backfire, just like we mentioned with visceral fat.

Not only is your body going through an empowering, but exhausting hormonal change, you’re also adding deprivation and survival mode into the mix, then expecting that extra layer of belly fat to disappear. By the way, that extra layer is your beautifully intelligent body adding protection and cushioning for your bones, as oestrogen supports bone strength.

My advice: do shorter fasts, such as 12 hours overnight, which many manage easily without feeling restricted. The key is nutrient dense meals during the day, 3-4 hours better meals without snacking and that solid overnight fast. 

Also focus on:

1. Protein at every meal to preserve muscle and support metabolism - aiming for 100-120g daily. 

2. Avoid coffee on an empty stomach to protect adrenal health - add MCT oil/powder with collagen or bone broth to prevent cortisol spikes.

3. Recovery and rest, because allowing your nervous system to recover and rest, is just as vital as your nutrition and movement.

These tweaks help women over 40 reap gentle metabolic benefits without triggering more stress.

Can You Lose Weight Without Intermittent Fasting?

Of course you can. A simple 12 hour fast, say 7pm to 7am, can do wonders. After 12 hours your body begins to burn visceral fat, so that overnight fast many already unintentionally do works beautifully for maintaining a healthy weight.

Plus, we shouldn’t be eating within 3+ hours of going to bed, to help optimise sleep quality - because the health benefits of sleep are based on quality, not just quantity. 

Doing 16–20 hour fasts, or even longer, just isn’t necessary unless under specialist guidance for diagnosed diabetes, cardiovascular disease or obesity. With support, fasting can bring benefits, but again, it’s all about context.

Now, here are some of my favourite nutrients to support healthy weight and visceral fat loss: 

1. Berberine: Often called ‘nature’s metformin,’ berberine mimics the metabolic benefits of intermittent fasting by helping balance blood sugar, improve insulin sensitivity, and reduce visceral abdominal fat without stressing the body or raising cortisol (stress hormone).

2. Bergamot HT: Clinically shown to help the body switch on fat burning pathways. The HT is a potent polyphenol from high quality extra virgin olive oil, the kind you’ll only find in premium olive oil (not supermarket bottles). It supports healthy cholesterol, reduces inflammation, lowers inflammatory visceral fat and helps the body process fats efficiently.

3. Magnesium: Your nervous system’s favourite mineral. Magnesium helps regulate blood sugar, reduce stress hormones, and support deep, restorative sleep, all key for hormone balance, healthy metabolism and lean muscle mass.

4. B vitamins: The body’s spark plugs, essential for energy, mood, hormones, and converting food into fuel. Particularly vital for stressed or busy women, as they deplete quickly when cortisol is high.

5. Vitamin D: A foundational nutrient for hormone balance and immune health. Adequate vitamin D helps regulate appetite, mood and fat metabolism, hence people with vitamin D deficiency tend to have an over active appetite, low mood and gain weight easily. 

6. Omega 3: One of the most potent anti-inflammatory nutrients you can take. Omega 3s from fish or algae help lower cortisol and reduce visceral fat by calming the body’s stress response from the inside out.

And remember, metabolic health isn’t only about food. Movement you enjoy, meaningful connections, and community all influence your hormones and how your body uses energy.

Simple habits like getting outside in the morning, breathing deeply, and sharing meals with others support your metabolism in ways fasting never could.

The Feminine Biohack: Nourishment Over Restriction

We hear the word biohacking daily. But is it too focused on pushing harder, tracking obsessively, and maximising your body on every level? Does biohacking for women look different? I think so, I believe it’s not about more control, but more connection.

When you blend science with self trust, you begin to recognise the signals your body sends like hunger, fatigue and intuition. This progress happens when you know why something works for you and when it doesn’t.

So, is intermittent fasting good for women?

Sometimes, yes - but it should never cost you your sleep, energy, menstruation or peace of mind.

Listen to your body, invest in understanding your physiology. You deserve to feel empowered by your choices, not punished by them.