What the Science Says and How I Approach It
Recently I did something a little different, I completed a GrimAge epigenetic test, as part of my annual health assessment done with the team at Health Screen which measures biological age using DNA methylation patterns.
The result showed my biological age is almost eight years younger than my chronological age.
That was encouraging, but the result itself is not the most important part.
What matters is what it reflects.
It reflects decades of consistent health habits, a lifestyle built around metabolic health, muscle preservation, whole foods and daily movement.
As a dietitian and founder of Be Fit Food, my entire career has focused on helping people improve their health in sustainable ways. After more than 18 years working with patients in hospitals, clinics and private practice, I have seen first-hand how powerful simple, consistent habits can be.
Biological age is not fixed. Increasingly, research shows it is modifiable, and lifestyle plays a major role in determining how quickly, or slowly our bodies age.
What Is Biological Age?
Chronological age is simply the number of years you have been alive.
Biological age reflects how your body is functioning at a cellular and physiological level. Two people can share the same chronological age but have very different biological ages depending on their health, lifestyle and metabolic function.
Scientists estimate biological age using a range of biomarkers, including:
• DNA methylation patterns
• Inflammation markers
• Metabolic health indicators
• Cellular stress pathways
• Cardiovascular and metabolic biomarkers
One of the most validated biological ageing measures is the GrimAge epigenetic clock, developed by Dr Steve Horvath and colleagues. It analyses DNA methylation patterns across the genome to predict mortality risk and healthspan.
Research shows GrimAge strongly predicts lifespan, cardiovascular disease risk and overall health outcomes. Importantly, it can also respond to lifestyle changes (Lu et al., 2019).
This means biological age is not simply predetermined by genetics. It reflects the environment your body is living in, including the food you eat, the activity you do, your sleep patterns, stress levels and metabolic health.
The Key Drivers of Biological Age
Ageing is complex, but research consistently highlights several biological systems that strongly influence how quickly the body ages.
1. Metabolic Health and Insulin Sensitivity
One of the strongest drivers of accelerated ageing is insulin resistance.
Chronically elevated blood glucose and insulin contribute to systemic inflammation, oxidative stress, vascular damage and mitochondrial dysfunction. Over time, these processes accelerate biological ageing and increase the risk of metabolic disease, cardiovascular disease and neurodegeneration.
Studies show improving metabolic health can slow ageing pathways and improve longevity markers (Barzilai et al., 2016).
For this reason, I prioritise nutrition that supports stable blood glucose and metabolic flexibility. In practice this means focusing on:
• whole foods
• plenty of vegetables
• high protein intake
• minimal added sugars
• balanced carbohydrates
Protein intake is particularly important. I aim for around 1.6 grams of protein per kilogram of lean body weight, which research shows supports muscle preservation and metabolic health (Morton et al., 2018).
2. Muscle Mass and Strength
Muscle is one of the most powerful predictors of longevity.
Low muscle mass is associated with increased mortality risk, metabolic dysfunction and reduced resilience with age. Resistance training improves insulin sensitivity, mitochondrial function, bone density and metabolic rate, while also supporting healthier inflammatory profiles.
A large body of research shows strength training reduces the risk of cardiovascular disease, metabolic disease and premature mortality (Westcott, 2012).
For this reason, strength training is non-negotiable in my weekly routine. My current training structure includes:
• strength training three times per week
• Pilates one to two times per week for mobility and core strength
• approximately 15,000 steps most days
• occasional high-intensity training
This combination supports both cardiovascular health and muscle preservation.
3. Chronic Inflammation
Inflammation plays a central role in ageing, often referred to as “inflammaging.”
Chronic low-grade inflammation contributes to cardiovascular disease, neurodegeneration, metabolic disease and immune dysfunction.
Diet quality, physical activity, sleep and stress management are all important regulators of inflammation. Diets rich in vegetables, fibre, polyphenols and healthy fats have been shown to reduce inflammatory markers (Calder et al., 2017). This is one reason I emphasise vegetable diversity and whole foods in my diet.
4. Recovery, Sleep and Stress
Sleep deprivation and chronic stress accelerate biological ageing.
Research shows inadequate sleep disrupts metabolic regulation, increases inflammation and impairs cellular repair processes. Stress hormones such as cortisol also influence ageing pathways including mitochondrial function and DNA repair.
Prioritising recovery is therefore just as important as exercise and nutrition.
5. Measuring and Monitoring Health
One of the biggest lessons I have learned over the years is that measurement creates accountability.
I test annually, including metabolic markers, body composition and now epigenetic age testing. Testing allows you to understand where you are today and make informed adjustments before problems arise.
Prevention requires awareness.
The Biggest Barrier to Health
After nearly two decades working with patients, the biggest barrier I see is not knowledge.
It is time.
People understand the importance of healthy eating, movement and sleep, but modern life often makes consistent execution difficult. Work, family responsibilities and busy schedules mean nutrition frequently becomes reactive instead of intentional.
This challenge is exactly why I created Be Fit Food.
Why I Created Be Fit Food
Be Fit Food was created to remove one of the biggest barriers to health improvement: time and convenience.
The meals were designed using the same nutritional principles I use in clinical practice. They are built around:
• high protein
• controlled carbohydrates
• high vegetable content
• no added sugars
• balanced portion control
This approach helps improve metabolic health, support fat loss and preserve muscle. Most importantly, it makes consistency easier.
When healthy food is accessible and ready, people are far more likely to maintain the habits that support long-term health. The meals I eat most days are the same meals our customers eat.
Prevention Matters More Than Treatment
One of the things that concerns me most is that our healthcare system largely focuses on treating illness after it develops, rather than preventing it.
Prevention requires education, access and practical tools. Improving metabolic health, building muscle and supporting good nutrition can significantly reduce the risk of many chronic diseases.
But these habits need to begin before illness develops.
The choices we make daily determine how our bodies function in the decades ahead.
Small Habits Shape Long-Term Health
Reversing biological age is not about chasing youth or searching for extreme anti-ageing interventions. It is about creating a lifestyle that supports the body’s natural repair systems.
For me that means:
• eating whole, nutrient-dense foods
• prioritising vegetables and protein
• strength training regularly
• staying active every day
• prioritising sleep and recovery
• measuring health markers annually
These habits are not extreme. They are simply consistent.
And over time, consistency compounds.
The small decisions you make every day quietly determine how your body functions in the future. If we focus on building strong metabolic health now, we give ourselves the best chance of living not just longer, but healthier lives.
References
Barzilai N., Crandall J., Kritchevsky S., Espeland M. (2016). Metformin as a Tool to Target Aging. Cell Metabolism.
Calder P.C., et al. (2017). Dietary factors and low grade inflammation in relation to overweight and obesity. British Journal of Nutrition.
Lu A.T., Quach A., Wilson J.G., et al. (2019). DNA methylation GrimAge strongly predicts lifespan and healthspan. Aging (Albany NY).
Morton R.W., et al. (2018). Protein intake to maximise resistance training induced muscle hypertrophy. British Journal of Sports Medicine.
Westcott W.L. (2012). Resistance training is medicine. Current Sports Medicine Reports.
