In recent years, intermittent fasting and prolonged fasting have been widely promoted as effective tools for weight loss, metabolic health, and longevity. While some women do feel benefits initially, many women particularly those in perimenopause and menopause find that fasting can unexpectedly lead to weight gain, increased stress, and hormonal disruption.

If you’re eating less, skipping meals, or doing extended fasts and still gaining weight through menopause, you are not alone and you are not broken.

Menopause Changes How Women Respond to Fasting

During perimenopause and menopause, levels of oestrogen and progesterone fluctuate and decline. These hormones play a significant role in:

Blood sugar regulation
Insulin sensitivity
Cortisol (stress hormone) balance
Thyroid function
Where and how the body stores fat

As these hormonal shifts occur, the female body becomes less resilient to physiological stress including the stress of intermittent/prolonged fasting.

What once felt energising in your 30s may now feel depleting, dysregulating, or inflammatory.

Why intermittent Fasting Can Lead to Weight Gain in Menopause

Although fasting is often framed as a way to “reduce calories,” the body doesn’t experience fasting as neutral. It experiences it as stress.

For menopausal women, intermittent fasting can contribute to weight gain through several mechanisms:

1. Increased Cortisol and Stress Load

Extended periods without food can raise cortisol, especially in women with already sensitive nervous systems. Elevated cortisol is strongly linked to abdominal weight gain, particularly during menopause.

2. Blood Sugar Instability

Low oestrogen reduces insulin sensitivity. Long fasting windows can worsen blood sugar swings, leading to fatigue, cravings, irritability, and compensatory overeating later in the day.

3. Thyroid Downregulation

Chronic under-fuelling can signal the body to conserve energy, potentially slowing thyroid function, which directly impacts metabolism and weight regulation.

4. Loss of Lean Muscle Mass

Menopause already increases the risk of muscle loss. Intermittent fasting without adequate protein intake can accelerate this, lowering basal metabolic rate and making weight gain more likely.

Fasting and the Nervous System: An Overlooked Piece

As a naturopath specialising in nervous system regulation, I see this pattern frequently: women using fasting in an attempt to “control” weight, while their nervous systems remain in a chronic state of activation.

For many women in menopause, fasting can push the body further into fight-or-flight, rather than supporting metabolic healing.

Signs fasting may be dysregulating your nervous system include:

Feeling wired but tired
Poor sleep or early waking
Increased anxiety or low mood
Strong sugar or carbohydrate cravings
Feeling worse, not better, over time

When the nervous system feels unsafe, the body prioritises survival over fat loss.

Weight Gain in Menopause Is Not Just About Calories

Menopausal weight gain is often driven by a combination of:

Hormonal shifts
Chronic stress
Poor sleep
Blood sugar dysregulation
Inadequate nourishment

In this context, eating less is rarely the solution.

In fact, many women see improvements in weight, energy, and mood when they shift from intermittent fasting to regular, protein-rich meals that stabilise blood sugar and support hormonal balance.

What to Do Instead of Intermittent or Prolonged Fasting

For many women navigating menopause, a more supportive approach includes:

Eating within an earlier window (e.g. 12-hour overnight fast rather than 16–24 hours)
Prioritising adequate protein at each meal
Supporting blood sugar with balanced meals (protein, fat, fibre)
Reducing overall stress load before targeting weight loss
Supporting liver, gut, and adrenal health
Working with — not against — your nervous system
A short term 5 day Fasting Mimicking Diet or FMD may be a lot more suitable and powerful. I have had great results using this in practice to support my clients to reset their metabolic system.

There is no single approach that works for every woman, especially during this life stage.

A More Compassionate Approach to Weight and Menopause

If intermittent fasting has led to weight gain, fatigue, or feeling disconnected from your body, it may be time to re-evaluate whether it’s truly supportive for you right now.

There are many types of fasting, and perhaps the one you are doing is not the right one for you.

Menopause is not a failure of willpower it is a biological transition that requires different inputs, different pacing, and often more nourishment, not less.

How Naturopathic Support Can Help

I have trained and worked at True North Health center in California so bring those expertise and knowledge of fasting to my practice. I can help you:

Understand your unique hormonal and metabolic picture
Regulate your nervous system
Improve energy, sleep, and mood
Support healthy, sustainable weight changes
Move away from restrictive patterns that no longer serve you

If you’re struggling with weight gain through menopause, fasting fatigue, or feeling confused about what your body needs, personalised support can make a significant difference.

If you’re looking for personalised menopause support that integrates natural medicine with a clear understanding of fasting types and benefits, working with a practitioner who respects both approaches can make all the difference. Book a free call to see what approach may be best for you.