You might have noticed your weight changing recently even though what you eat has not really changed. These shifts are partially due to hormonal changes during perimenopause, and understanding what sits behind them can help you work with your body. If you already live with PMOS (polyendocrine metabolic ovarian syndrome, formerly PCOS), some of this may feel familiar, though perimenopause adds its own layers.
Why weight distribution shifts as oestrogen declines
Oestrogen is a key factor that shapes where your body stores fat. As your oestrogen levels drop during perimenopause, fat that used to sit around your hips and thighs tends to move towards your middle instead. This is the hormone change at work, and it can happen whatever your eating or activity habits look like.18
Some of that fat around your middle is visceral fat, the kind stored deeper around your organs rather than just under your skin. During the menopause transition it can climb from around 5 to 8 per cent of your total body fat to around 10 to 15 per cent, though these are rough figures and the range between people is wide. Visceral fat carries more weight for your heart and metabolic health, which is why this particular shift is worth knowing about.9
How metabolic rate changes during perimenopause
Alongside this shift, the amount of energy your body uses may gradually change through midlife. This is in part due to gradual loss of lean muscle that happens with age. Muscle burns more energy at rest than fat does, so as muscle drops, your body needs fewer calories to tick over. If your eating has stayed the same, that shift alone can nudge your weight up slowly over time, so working to preserve muscle is important.2
On average, weight gain of around 1.5 kg has been observed during each year of the menopause transition, though this varies a lot from person to person. If you live with PMOS, with existing insulin resistance or other metabolic features you may find these changes overlap, making them harder to distinguish from patterns you already recognise.10
Why restricting food often makes things harder
When the scales go up, it is common to want to cut calories hard. During perimenopause, that approach tends to work against you. Cutting back sharply can lead to a greater loss to lean muscle, and since muscle keeps your metabolism ticking over, losing it slows things down even more. Over time that can make your weight harder to manage.11
What helps: protein, fibre, and a balanced approach
Instead of eating less overall, leaning on foods that help support muscle and feel full can make a real difference. Protein matters here. Mixing up your protein sources, beans, peas and lentils alongside other choices, can help you feel fuller for longer and helps protect your muscle at a time when it tends to slip away.34
High-fibre foods like wholegrains, fruit and vegetables are a key part of a balanced diet and may help you keep your weight steady. Building your meals around enough protein and fibre gives you a steady base to work from.5
What this means if you have PMOS
If you live with PMOS, the perimenopausal shift which often impacts metabolism, insulin sensitivity and where you hold fat, can add an additional layer to the patterns you already work with. In this situation the same principles hold: enough protein and fibre, steering clear of harsh restriction, and protecting your muscle. How PMOS and perimenopause play off each other hormonally is worth raising with your GP, who can look at your own picture.
Weight changes during perimenopause come from real shifts in your physiology. If you want to look into this more, a GP or registered dietitian can give you guidance tailored to where you are in your transition.