Perimenopause and Weight Gain: Why It Happens and What You Can Do

If you’re in your 40s and wondering why your jeans suddenly feel tighter, even though nothing has changed with your diet or routine, you’re not imagining it. Weight gain in perimenopause is incredibly common, and it’s not just about calories in vs. calories out.

As a nutritionist who specialises in women’s hormone health, I work with many clients navigating this transition. The good news? Weight gain during perimenopause is understandable, manageable, and not something you have to “just live with.”

Let’s explore why it happens and what you can start doing today to feel more in control of your body again.

Why Does Weight Gain Happen During Perimenopause?

Perimenopause is the 4–10 year transition leading up to menopause, where hormone levels, especially pestrogen and progesterone, begin to fluctuate and decline.

These hormonal changes can cause:

• A slower metabolism
  You may burn fewer calories at rest due to shifts in thyroid hormones, oestrogen, and muscle mass.

• Insulin resistance
  As oestrogen drops, your body becomes less sensitive to insulin, making it easier to gain fat—particularly around the belly.

• Increased cortisol (stress hormone)
  Perimenopause often overlaps with high-stress life stages, and elevated cortisol promotes fat storage and sugar cravings.

• Poor sleep
  Hormonal sleep disruption affects hunger hormones like leptin and ghrelin, increasing appetite and cravings the next day.

This isn’t about “willpower.” Your hormones are changing—and your nutrition needs to change with them.

3 Tips to Support Healthy Weight in Perimenopause

1. Prioritise Protein with Every Meal

Protein helps preserve lean muscle, supports a healthy metabolism, and keeps you fuller for longer. Aim for 25–30g per meal. Think: eggs, Greek yoghurt, fish, tofu, or quality protein powders.

2. Balance Blood Sugar

Stabilising blood sugar reduces cravings, improves energy, and supports hormonal balance. Focus on meals that combine protein, healthy fats, fibre, and complex carbs, and avoid skipping meals or relying on sugar for energy boosts.

3. Manage Stress + Support Recovery

Chronic stress raises cortisol, which contributes to belly fat and insulin resistance. Gentle movement like walking, strength training, yoga, and prioritising sleep can all support nervous system balance and fat metabolism.

Ready to Feel Like Yourself Again?

Navigating perimenopause isn’t just about managing symptoms - it’s about understanding your body’s new normal and learning how to work with it, not against it.

As a nutritionist who specialises in hormones, metabolism, and women’s health, I help you identify what’s really driving your weight changes and create a plan that’s nourishing, personalised, and sustainable. You don’t need restrictive diets or more stress—you need support, strategy, and balance.

Book a free introductory call to chat about your symptoms and goals. Whether you’re dealing with unexplained weight gain, fatigue, mood changes, or poor sleep, we can create a clear, supportive path forward - together.

Megan Hallett and the content provided are not intended to treat, diagnose, cure or prevent any disease. All material on meganhallett.com is provided for educational purposes only. Always seek the advice of your doctor and/ or another qualified healthcare provider for any questions you have regarding a medical condition, and before undertaking any diet, supplement, exercise or other health-related programs.