What Is the Biggest Factor That Affects Aging?

When people talk about ageing, they often blame it on genetics, stress, or simply getting older.

That sounds logical, but science paints a clearer picture.

The biggest factor in how fast and well we age is our metabolic health. And the important thing to know is this: metabolic health is shaped mostly by everyday habits, not by luck or family history.

The Short, Honest Answer

If we had to name one thing that matters most for ageing, it would be how healthy your metabolism is.

Metabolic health is about how well your body manages energy. It affects blood sugar, body fat, inflammation, and how hard your organs have to work to keep you going.

When metabolism is strained, the body wears down faster. When it is balanced, ageing tends to slow.

What Metabolic Health Really Means

Metabolic health isn’t a medical buzzword. It simply reflects how smoothly your body is running day to day.

A healthy metabolism means your body can handle food, movement, and stress without being constantly inflamed or overloaded. 

In Phytotherapy/naturopathy, there is a class of herbs called adaptogens to build resilience. This is one of the secrets of longevity. The Holistic Vitality programme by Dr Liew is designed to build holistic vitality. 

A struggling metabolism, on the other hand, often manifests as weight gain, low energy, elevated blood sugar, or cholesterol issues.

Over time, those problems don’t just increase the risk of disease — they also speed up biological ageing inside the body, even if you still feel “fine” on the surface.

Why Lifestyle Matters More Than Genetics

Genes do influence ageing, but they don’t decide everything.

Think of genes as a rough blueprint. They may increase or reduce risk, but they don’t control how quickly damage builds up. That part is mostly shaped by how we live.

Large human studies show that people with healthier habits often age more slowly than those with poor habits — even when genetics aren’t on their side.

In simple terms, genes matter, but lifestyle usually matters more.

In fact, lifestyle is associated with 80% of diseases. 

The Lifestyle Factors That Affect Ageing the Most

When researchers look at ageing, they don’t see one single habit acting alone. Instead, they see a small set of everyday behaviours that repeatedly emerge as the strongest drivers of faster ageing. These habits all affect the same thing: metabolic health.

Here are the most important ones, in order.

1. Excess Body Fat and Obesity

This is one of the clearest and strongest links to faster ageing.

Carrying too much body fat puts the body under constant strain. It increases inflammation, disrupts hormone balance, and makes it harder for the body to manage blood sugar properly. Over time, this creates the perfect conditions for faster cellular ageing.

Extra body fat tends to:

• Increase long-term inflammation
  
• Disrupts normal hormone balance
  
• Raise blood sugar and insulin levels
  
• Speed up damage inside cells
  

What’s important to understand is that this doesn’t only apply to severe obesity. Research shows that even slow, gradual weight gain over the years can quietly speed up biological ageing.

2. Poor Diet

What we eat every day matters more than most people realise.

A poor diet doesn’t age the body overnight, but it steadily pushes metabolism in the wrong direction. Diets that speed up ageing are usually built around convenience rather than nourishment.

These diets tend to be high in processed foods and added sugar, and low in vegetables and fibre. Over time, they increase inflammation and make blood sugar harder to control.

On the other hand, diets linked to slower ageing are usually simpler than people expect. They tend to include plenty of vegetables, mostly whole foods, healthy fats, and balanced meals.

Food affects aging not because of trends or superfoods, but because of how it supports or strains metabolism and inflammation day after day.

However, please do not go on an extreme or fad diet. 

The best diet is moderation, taught by Sebastian Liew. And he called it – The holistic vitality diet.  

You can learn more in the Holistic Vitality Diet, taught by Dr Sebastian Liew. This is usually taught to all his patients. 

3. Lack of Physical Activity

You don’t need extreme workouts to protect your health.

What matters most is regular movement. When the body moves often, it handles blood sugar better, keeps inflammation lower, and maintains muscle and organ function.

Regular movement helps to:

• Keep the weight more stable
• Improve blood sugar control
• Lower inflammation
  
• Support muscles, bones, and organs
  

People who stay active — even with simple daily movement — tend to age more slowly than those who are mostly inactive, including in later life.

Begin with regulation, one of the 7 terrains taught by Sebastian Liew in his book, My Healing Life. Buy here – https://leaftolife.com.sg/product/my-healing-life-book-the-most-important-work-in-life/

4. Chronic Inflammation

Inflammation is a quiet problem because you usually don’t feel it happening.

When inflammation persists for long periods, it slowly damages the body from within. Cells don’t repair as well, blood vessels become less healthy, organs work less efficiently, and even DNA can be affected.

Long-term inflammation damages:

• Cells
  
• Blood vessels
  
• Organs
  
• DNA
  

It is commonly driven by poor diet, excess weight, lack of movement, and smoking. This slow, ongoing damage accumulates over time and plays a major role in accelerating ageing.

Get your inflammation markers checked – Homocysteine, C-reactive protein. 

During his holistic assessment during the consultation session, Dr Liew can share your tissue type with you, which indicates whether you need to support and balance your immune system. Book an appointment – +6588207661 

5. Smoking

Smoking remains one of the fastest ways to age the body.

It increases inflammation, damages blood vessels, and accelerates disease across nearly every system in the body. Compared with many other lifestyle factors, the effect of smoking on aging is strong and well-documented.

Smoking:

• Raises inflammation
  
• Damages circulation
  
• Speeds up disease development
  
• Shortens healthy lifespan
  

Even when compared to diet or inactivity, smoking clearly pushes ageing forward more aggressively.

6. What About Stress, Mental Health, and Environment?

These absolutely matter, but mostly because of how they affect daily behaviour and biology.

Long-term stress can disrupt sleep, increase inflammation, encourage unhealthy eating, and reduce physical activity. Poor environments can limit healthy choices. Mental health struggles often make self-care harder.

What is stress? 

Anything, whether physical or emotional, that you perceive as threatening to your survival and identity, and that, if chronic, leads to physiological manifestations.

What kind of stressors lead to poor health?

• Unexpected events such as the death of a loved one or loss of a job
• Highly emotional, such as constant scolding by someone
• Repression of emotion 
• Isolated. Not allowed to talk about it
• Cannot find a way out of the situation – melancholic 

There are plant medicines that can help to process the stress. One powerful remedy is Phytoxin – https://leaftolife.com.sg/product/leaf-to-life-phyto-xin/

So while these factors influence ageing, they usually do so by damaging metabolic health, rather than acting alone.

The Big Picture

Aging is not caused by one single habit or one bad year.

But when researchers look across long-term studies, molecular aging markers, and population health data, the same pattern keeps appearing:

Metabolic health — shaped by what we eat, how we move, and how much strain we place on the body — is the biggest factor affecting how fast we age.

The encouraging part is that metabolic health is not fixed. It can improve at almost any age.

Ageing isn’t just about time passing.
It’s also about how gently — or harshly — we treat the body along the way.