Intermittent fasting: helpful structure or just hunger with branding?
Intermittent fasting has been sold as the clever, science‑backed way to eat less without dieting. Depending who you listen to, it fixes everything from weight and blood sugar to brain fog, gut health, skin and perimenopause symptoms.
For some people, changing when they eat genuinely does feel easier than counting calories. But fasting isn’t neutral, especially for women, and the newer research is a bit less shiny than the Instagram version.
The question isn’t “is intermittent fasting good or bad?” It’s: “is this way of eating helpful for your body, nervous system and life right now?”
What intermittent fasting can actually do
There are a few different patterns (16:8, 14:10, 5:2, alternate‑day, etc), but the core idea is simple: eat in a shorter window or on fewer days, and you’ll usually end up eating less overall. Research in adults with overweight or obesity suggests that, on average:
intermittent fasting can lead to similar weight loss to standard calorie reduction, not dramatically more
some people see improvements in waist circumference, blood lipids, fasting glucose and insulin sensitivity
benefits seem to come mainly from overall energy reduction and giving the body a regular break from eating, not a magical fasting state unique to one schedule
In other words, it can be one possible structure for weight and metabolic support, particularly for people who like clear boundaries around meal times. But that’s only half the story.
The newer cardiovascular red flag
A big piece of data that changed the conversation came out in 2024–2025. An analysis of over 20,000 US adults found that people who routinely ate in less than an 8‑hour window each day (the classic “16:8” pattern) had a higher risk of cardiovascular death compared with those eating over 12–16 hours. This was especially true in people who already had heart disease or cancer. Important nuance:
This was observational data, so it shows association, not proof that fasting caused the problem.
The eight‑hour eaters might have been unwell in other ways, or using fasting in a compensatory way.
Still, it’s a strong enough signal that major heart organisations are now taking a more cautious stance on aggressive time‑restricted eating, particularly long‑term and in people with existing health conditions.
For most women just trying to feel human again, that’s a good reminder that more extreme is not automatically better.
How fasting can land differently in women
Women’s bodies are not small men’s bodies. Sex hormones, stress hormones and appetite signals are much more intertwined. Things I see clinically, and that emerging research and expert commentary are starting to highlight:
Longer fasting windows can disrupt ovulation and menstrual cycles in some pre‑menopausal women, especially if combined with stress, intense exercise or under‑eating.
Some women notice more anxiety, sleep disruption, mood swings, hair shedding or acne flare‑ups if fasting becomes too aggressive or rigid.
Perimenopausal and menopausal women can find shorter eating windows helpful if they still eat enough overall and don’t pair fasting with very low‑carb, very low‑calorie patterns that push stress hormones through the roof.
None of this means women can’t fast. It means fasting is a stressor – like high‑intensity training or cold plunges – and you need to know how many stressors your system can realistically cope with.
If you already feel wired‑tired, hangry, under‑slept and overloaded, cutting your eating window to 6–8 hours isn't like to be the most supportive thing you could do.
When intermittent fasting might be reasonable
There are situations where a gentle version of fasting can be helpful:
You naturally don’t like big late‑night meals, and a 12:12 or 14:10 pattern (for example, breakfast at 8, last food by 8 or 6) feels enjoyable and sustainable.
You tend to graze constantly into the evening, and giving yourself a clear “kitchen closed” time helps your digestion and sleep.
You’re working on metabolic health with medical support, and a modest eating window is one tool among many (not the only strategy).
In those cases, I care far more about:
what you do eat in your window (protein, fibre, colour, healthy fats, enough energy)
your meal timings inside that window (three decent meals vs one frantic binge)
how your mood, hormones, skin, bowel habits and energy respond
than about hitting a precise number of fasting hours.
When fasting is a bad fit
Fasting is usually not the right tool if:
You have a history of disordered eating, binge‑restrict cycles or rigid food rules.
You’re already skipping breakfast and then falling face‑first into the biscuit tin at 4pm.
You feel faint, shaky, ragey or out of control when you get too hungry.
You’re dealing with significant stress, burnout, poor sleep, PMS or rocky perimenopause symptoms and your nervous system is already maxed out.
You’re pregnant, breastfeeding, underweight, recovering from illness, or have certain medical conditions where fasting is unsafe.
In those situations, tightening your eating window often worsens the very symptoms you’re hoping to fix: more cravings, more skin flares, more brain fog and more binge‑y behaviour. Often what helps far more is:
stabilising blood sugar with regular, balanced meals
supporting gut health with gentle changes
getting curious about hormones, thyroid, nutrients, sleep and stress
reducing the overall load on your nervouse system, not adding to it
What to focus on instead
If you’re drawn to fasting because you feel puffy, exhausted, spotty or stuck with a weight that won’t budge, it’s understandable. It promises structure when everything feels chaotic.
But whether you fast or not, the foundations that support skin, gut, hormones and energy look surprisingly similar:
Eating enough across the day so your body isn’t constantly in “famine then feast” mode. That alone calms a lot of blood sugar crashes and cravings.
Building meals around protein, fibre‑rich carbs and healthy fats, such as that found in the Mediterranean way of eating
Avoiding swinging between restriction and “cheat” weekends.
Supporting sleep and stress so your nervous system isn’t screaming constantly.
Checking in on the basics with your GP – iron, B12, thyroid, blood sugars, lipids – and using tests like stool testing, hormone panels or others only when they’re likely to change what you do.
If you then choose to have a gentle overnight fasting window on top of that, great.
If you’re in the messy middle with fasting
If you’ve tried 16:8 (or 18:6, or OMAD…) and ended up tired, binge‑y, more obsessed with food or more anxious around eating, you haven’t failed at fasting. It probably just isn’t the right tool for your body right now. What usually helps is stepping back and asking:
What’s the actual problem I’m trying to solve – skin, gut, weight, cravings, perimenopause chaos, fatigue, all of the above?
What happens to my mood, energy, bowels and sleep when I fast vs when I eat regularly?
Is this way of eating moving me towards a calmer relationship with food – or back into food rules and food noise?
If you’d like to find a way of eating that supports your gut, hormones and skin, you can book a free introductory call with me so we can talk it through.