How to Eat for Healthier Aging: 10 Science-Backed Rules

I recently asked Longevity Code subscribers what they find hardest about building a healthier lifestyle.

A few common themes came up:

• “There’s so much nutritional information out there. I’m overwhelmed.”

• “I eat well - but I’ve no idea if my diet is optimised for aging.”

• “I want a step-by-step dietary framework I can stick to long term.”

I hear you.

Life is complicated enough without making healthy eating complicated too.

So over the next month, I’m going to make eating for healthier aging simple and practical - giving you a clear framework for supporting your biology and health for the long term.

Let’s start with the foundations.

Quick Note: This is Week 1 of the How to Eat for Healthier Aging mini-series. Over the next 3 weeks, we’ll explore the most evidence-backed foods, dietary strategies and targets for healthy aging - and turn them into a comprehensive framework you can follow sustainably.

This first edition is free for everyone. The rest of the series will be released every Tuesday for paid subscribers.

Large population studies consistently find a similar dose-response pattern: the more of your diet that comes from minimally processed foods rather than ultra-processed foods, the lower your risk of most major chronic diseases and early death.

Everything else is built on this.

The trillions of microbes living in your gut thrive on the diverse fibres and plant compounds you provide them, so 30+ different plants is an evidence-based way to support your microbiome and the gut, immune and metabolic systems it interacts with.

It’s more doable than it sounds - think herbs, spices, tea, coffee, vegetables, fruit, beans, nuts and seeds.

Protein provides the amino acids needed to maintain and repair muscle and make enzymes, hormones and immune proteins. As we age, our muscles become less responsive to protein, so around 1.2-1.6 g/kg/day, spread across meals, is a good evidence-based target for active adults.

Fibre keeps your gut moving, helps regulate blood glucose and cholesterol, and provides fuel for your gut microbes. Higher intakes are consistently linked with lower all-cause mortality.

Aim for at least 30-35g a day, ideally from a wide variety of plant foods.

Your cells depend on vitamins and minerals such as folate, B12, zinc, iodine, magnesium and vitamin D for energy production, DNA synthesis and repair, immune function and nervous-system health.

Nutritional adequacy matters just as much as hitting your other targets.

Unsaturated fats get built directly into your cell membranes, where they influence how those cells signal and respond, and can improve your blood lipid profile to support cardiovascular health.

Make extra-virgin olive oil your default, eat nuts and seeds often, and get omega-3s from fatty fish twice a week.

Polyphenols are natural bioactive plant compounds that help protect your cells from damage and lower inflammation. Including a variety in your diet - like berries, olive oil, red grapes, herbs and coffee - is a simple daily habit linked with a lower risk of chronic disease.

Glucose rising after a meal is normal - the goal is to avoid frequent, large spikes from refined carbohydrates and sugary drinks, which over time can impair metabolic health and drive insulin resistance.

Choose minimally processed carbs and pair them with protein and fibre.

Your body handles food differently throughout the day - insulin sensitivity and glucose tolerance are generally better earlier, so keep meal timing consistent, eat more of your food earlier and avoid heavy meals close to bedtime.

Diet is one of the biggest modifiable influences on chronic inflammation, so build your diet around plants, fibre and healthy fats while limiting ultra-processed foods, processed meats, excess alcohol and excess calories.

Also pay attention to any food allergies or intolerances where repeated exposure may be triggering ongoing immune activation.

That wraps up Week 1 of the How to Eat for Healthier Aging mini-series. Over the next 3 weeks, I’ll be turning the science into a practical, sustainable system you can use.

Next week: 30 Foods I Build My Diet Around - including a weekly shopping list and micronutrient table, so you can easily put it into practice.

Subscribe now so you don’t miss it.

Let me know in the comments or by replying to this email what your diet currently looks like, and if there’s anything specific you’d like me to cover in the rest of the series.

Thanks for reading!

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Disclaimer: This post provides educational information based on scientific research and is not medical advice. It does not establish a doctor-patient relationship. Always consult a qualified healthcare professional before making lifestyle changes, addressing medical conditions, or starting new treatments.