Understanding why your body can respond differently to the same food and exercise during perimenopause and menopause
If you've reached your 40s or 50s and feel as though your body is suddenly responding differently to food and exercise, you're certainly not alone.
Perhaps you're eating much the same way you always have, but your waistline is changing. Maybe you're exercising regularly but not seeing the results you used to. Or perhaps losing a few kilos now seems much harder than it did in your 30s.
One of the most common things I hear from women during perimenopause is:
“I haven't really changed what I'm doing. So why is my body changing?”
It's an understandable question, and an important one.
The key thing to recognise is that although your habits may not have changed dramatically, the physiological environment in which those habits are operating may have. Your hormones, body composition, muscle mass, energy requirements and sleep can all shift during midlife. This means the same approach to eating or exercising that worked well for you previously may not produce the same response now.
Understanding why can be far more useful than simply assuming you need to eat less or exercise more.
The same lifestyle doesn't always mean the same result
We often think about weight in relatively simple terms. If we're eating the same amount and exercising the same way, shouldn't our weight remain fairly stable?
The body is more complex than that.
As we move through perimenopause and menopause, changes occur that influence where we store fat, how much lean muscle we carry, and how much energy our bodies require. So while your daily routine might look much the same on the outside, what's happening inside your body may be quite different.
Your body composition may be changing
One of the most noticeable changes during the menopausal transition can be a shift in body composition.
As oestrogen levels fluctuate and eventually decline, fat distribution may change. Rather than carrying more weight around the hips and thighs, some women begin to notice more fat accumulating around the abdomen. At the same time, lean muscle mass naturally tends to decline with age.
This can create a situation where the number on the scales doesn't tell the whole story. You may weigh a similar amount but notice that your clothes fit differently, your waist circumference has changed, or your body simply doesn't feel the same. Looking only at body weight can sometimes be misleading, which is why body composition and waist circumference can also provide useful information.
Muscle changes the equation
Muscle is important for much more than strength and appearance. It is metabolically active tissue and plays an important role in how much energy your body uses, as well as supporting glucose regulation, mobility, physical independence and healthy ageing.
This is also why the focus at this stage of life may need to shift from simply eating less towards eating differently, with greater attention to protein, fibre, food quality and supporting muscle and metabolic health.
Muscle mass naturally declines with age, and the menopausal transition may contribute to this change. If you gradually have less lean muscle than you did ten or fifteen years ago, your body's energy requirements may also be different, which helps explain why eating exactly as you did in your 30s doesn't necessarily mean your body will respond the same way it did then.
A more useful question than “how much should I cut back?” may be:
“Am I giving my body what it needs to maintain muscle and metabolic health at this stage of life?”
This is one reason adequate protein and resistance exercise become increasingly important during midlife.
Oestrogen affects more than your menstrual cycle
We often associate oestrogen primarily with periods, fertility and menopausal symptoms. But oestrogen also has broader effects throughout the body and is involved in energy balance, appetite, fat distribution and insulin sensitivity.
As oestrogen levels fluctuate during perimenopause and menopause, some of these metabolic influences can shift as well. This doesn't mean oestrogen is solely responsible for midlife weight changes, but it does mean that the hormonal environment your body is working within is different from the one you had earlier in adult life. Your body at 48 is not operating under exactly the same conditions as your body at 28 or 35, and that's an important distinction.
Insulin sensitivity can also become part of the picture
Insulin is a hormone that helps move glucose from the bloodstream into our cells, where it can be used for energy. When cells become less responsive to insulin, the body may need to produce more insulin to keep blood glucose within its normal range.
Changes in oestrogen, body composition and muscle mass during midlife may all influence insulin sensitivity. This doesn't mean every woman going through perimenopause or menopause will develop insulin resistance; rather, it's another reason why I encourage women to look beyond weight alone and think more broadly about metabolic health.
Blood glucose regulation, waist circumference, blood pressure, cholesterol, strength and energy levels can all contribute useful information about what's happening in your body.
Sleep can change the equation too
Another thing that may have changed, without you consciously changing your lifestyle, is your sleep.
Hot flushes, night sweats, stress and early waking are common experiences during the menopausal transition. And poor sleep can have a ripple effect. When you're tired, you may move less without even noticing. Exercise can feel harder. Hunger or cravings may change, and making the food choices you would normally make can require considerably more effort.
So when a woman tells me, “I'm doing everything the same,” one area I may also explore is: “Are you sleeping the same?”
Because sometimes it isn't the obvious habits that have changed.
Perhaps the question isn't “How can I eat less?”
When our body changes, it's very easy to respond by restricting food. But in midlife, I prefer to look at whether your current way of eating and moving is supporting the body you have now.
For example:
- Are you eating enough protein across the day to support muscle?
- Are you including resistance exercise as well as walking or cardiovascular exercise?
- Are you getting enough fibre and a good variety of whole foods?
- Has your sleep changed?
- Are stress and recovery affecting your energy or activity levels?
- Are you looking only at your weight, or at your broader metabolic health as well?
These questions open a very different conversation, and often a more useful one.
Your body hasn't suddenly forgotten how to work
Perimenopause and menopause represent significant physiological transitions. That doesn't mean healthy eating and exercise have stopped working. It means the way you support your body may need to evolve as your body changes.
Maintaining muscle, eating adequate protein, staying physically active, supporting good sleep and paying attention to metabolic health can all become increasingly important during this stage. And importantly, eating well during midlife doesn't have to mean restriction, deprivation or spending every day thinking about your weight.
The goal is to nourish and support your body in a way that is realistic, sustainable and appropriate for this stage of life.
Look at the bigger picture
If you've been wondering why your waistline or body composition is changing even though you don't feel you've changed your lifestyle very much, there may be more going on than simply how much you're eating. Hormonal changes, muscle mass, body composition, insulin sensitivity, sleep and changing energy requirements can all form part of the picture.
For a broader explanation of the factors that can contribute to weight gain during menopause, including exercise, nutrition, sleep and other metabolic considerations, you can also read my earlier article on this topic.
And if you're finding that your body has changed during perimenopause or menopause and you're not sure where to start, individualised support can help you look at the bigger picture and identify what's most relevant to you.
Warmly,
Carine 🌿
