Insulin Resistance and Metabolic Health in Your 40s: A Practical Guide

Standard tests like fasting glucose and HbA1c often look "fine" long after insulin resistance has quietly taken hold. By the time those numbers move, the pattern has been building for years. The good news: this is one of the most reversible things in the body.

The markers that move first

Look earlier and wider than glucose. The triglyceride-to-HDL ratio (TG:HDL) is a simple, powerful proxy for insulin resistance; pair it with fasting insulin, ApoB, and waist-to-height ratio. A TG:HDL above roughly 2, a rising fasting insulin, or a climbing ApoB tell you the metabolism is under strain long before glucose or HbA1c react.

Early signs worth noticing

• Afternoon energy crashes.

• Frequent sugar or carb cravings.

• Weight settling around the middle.

• Feeling hungry again soon after eating.

• Brain fog.

Food and movement levers

• Build meals around protein, fibre and healthy fats, with refined carbs and sugar as the exception.

• Walk after meals to help muscles use up blood sugar.

• Strength-train to build the muscle that improves insulin sensitivity.

• Protect sleep and manage stress — both move blood sugar more than people expect.

Metabolic health in your 40s is very much reversible. It starts with the right markers and the right next small step — evidence-informed changes that fit your life, not rigid rules or quick fixes.

A quick note: this is educational and reflects how I work with clients — general information to learn from, not a personalised plan.

Want to get ahead of it? Book a free discovery call.

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PCOS: a functional medicine lens · Perimenopause in your 40s · Work with me — the coaching programme

About the author

Shivani Hariharan is a functional medicine health coach (IAFM-certified, FMCA-trained) helping midlife adults work on the root-cause habits behind hormone, thyroid, gut and metabolic health. Learn more about Shivani or book a discovery call.