Metabolism is the combination of all the chemical processes in your body that convert food and drink into energy, and produce important building blocks to maintain a healthy body.
This energy creates the building blocks for cell growth, for cell and DNA repair, for running your brain, heart and immune system. The stable maintenance of all your body’s systems.
So metabolic health is central to staying healthy and longevity. Because without energy, there’s no life. And without health, longevity surely has limited appeal.
Good metabolic health means your body converts food into energy efficiently, uses insulin effectively, regulates blood sugar, maintains healthy blood pressure, manages the metabolism of blood fats, and absorbs and utilises nutrients optimally.
Sub-optimal metabolic health, (which is very common and often undiagnosed), is linked to excess glucose in the blood stream, weight gain, and to chronic inflammation which underlies so many age-related diseases.
An important 2026 study1also links poor metabolic health to the excess build-up of sugar-based structures on proteins in the brain, (called hyper-glycosylation), and as a significant factor in Alzheimer’s.
In this article, we explain how to improve and maintain your metabolic health over the long term—not only to stay healthy, but also to help slow the ageing process itself.
It’s advice I follow myself and, in a recent whole body clinical test, my metabolic age was rated as 15 years less than my chronological age.
But first some background
Metabolism is divided into two main processes:
Catabolism and Anabolism
Catabolism: is the break-down of carbohydrates, proteins, and fats into smaller molecules. For example, carbohydrates are broken down into glucose, to be used immediately for energy or stored as glycogen in muscles and the liver.
Catabolic reactions generate ATP, the energy molecule that is continuously generated in your mitochondria. You create a truly astonishing amount of ATP. Indeed, you create your body weight of ATP – a day2!! Because it’s made, used and re-made continuously.
Anabolism: is the opposite, the build-up of smaller molecules into larger structures, like DNA, proteins and thus tissues. This process consumes energy and is essential for tissue repair, muscle growth, and bone development.
Metabolic health requires that catabolism and anabolism are balanced.
Your Metabolic Rate and Weight
Your basal metabolic rate (BMR) is the number of calories your body needs to maintain its basic functions, while at rest. For most, that uses 60–70% of your calorie intake.
A BMR for men varies between 1,450–2,000 calories/day depending on their age group. Younger men having a higher BMR – which is why men (and women) tend to put on weight as they get older. The equivalent for BMR for women is 1,150–1,600 calories/day.
Age, muscle mass, and your activity level influence your metabolic rate. Your metabolic rate declines by between 1% and 2% a year after 609
What are the Key Markers of Metabolic Health?
Metabolic health is usually assessed using the five following main markers. You’ll see that 3 need health professional input:
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Waist circumference: An ‘apple’ shape stomach Indicates abdominal fat around the main organs. It means a waist circumference of over 40 inches in men and is a danger signal for heart disease. In women it’s more frequently a ‘pear shape’ with a waist of over 35 inches Indicating abdominal fat around the main organs. This type of fat is an increased risk for metabolic dysfunction and diabetes.
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Fasting blood glucose: Your fasting glucose level is a simple test your doctor can do. The British Heart Foundation state it should be between 3.9 and 5.4 mmol/L Higher levels indicates prediabetes or diabetes3
With high levels of circulating blood sugar, your cells and tissues can become hyper-glysolated. Proteins become bound to sugar molecules (think ‘sugar-coated)! This changes the proteins’ shape and prevents them from functioning properly.
In a normal metabolic state, Insulin is produced to reduce excess blood sugar levels and restore levels to normal. But if blood sugar is continuously high over a long period, this reaction becomes muted and insulin resistance can develop., leading to Type 2 diabetes. Diabetes, in turn, risks damage to the heart, kidneys and eyes.
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Blood pressure: It is recommended that your systolic and diastolic readings should be at or below 120 mmHg and diastolic 80 mmHg. What’s called stage 1 hypertension is indicated by levels of 130-139/80-89 mmHg.
A blood pressure monitor and a regular check is a good investment for over 60’s because high blood pressure is not only a risk factor for heart disease and stroke, but dementia. This link takes you to the official NHS advisory website NHS Blood Pressure Chart - BP Calculator | Official UK Guidelines
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Triglycerides: These are fats circulating in your blood stream. At normal levels they are important fuel for your body. The liver makes triglycerides, but most triglycerides form from the fat-containing foods we eat. If we take in too many calories from sweet, sugary foods, drinks, and alcohol, our liver converts these into excess triglycerides.
The recommended triglyceride norms in the UK are below 2.3 mmol/L non-fasting, and fasting triglycerides should be below 1.7 mmol/L. Above these levels indicates poor fat metabolism and increased cardio-risk4.
5. Cholesterol: As you’ll know you have two types of cholesterol – HDL and LDL commonly known respectively as ‘good and ‘bad’. A healthy level of total cholesterol is below 5mmol/L and for HDL is above 1.0mmol/L for men and above 1.2mmol/L for women. LDL cholesterol should be below 4mmol/L
Cholesterol gets a bad rap – but it is essential as it supports steroid and sex hormone production and is vital to create cell membranes. It’s involved in the formation of vitamin D and therefore indirectly important for healthy bones and immune function.
It’s high LDL and high total cholesterol, leading to the buildup of plaque in arteries, that’s the danger. HDL helps remove LDL from the blood stream.
Metabolic Syndrome
Having three or more abnormal markers may signal what is called metabolic syndrome.
The danger with metabolic syndrome is that – without a check-up - there may be no obvious symptoms, until serious a disease emerges. So, an annual or bi-annual check of your blood markers is highly recommended.
Metabolic Syndrome increases your risk of type 2 diabetes, heart disease, stroke, fatty liver disease, polycystic ovarian syndrome (PCOS) in women and erectile dysfunction in men.
Summary: Guarding your metabolic health is very important. It’s estimated5 that some 37% of adults have metabolic syndrome – rising to 50% of over 60’s! And most will not be aware.
Metabolic health and your brain
Alzheimer’s is characterised by abnormal proteins in the brain – specifically tau tangles and beta amyloid. But is that cause or effect?
There is an increasing view, supported by a 2026 study1, that mitochondrial dysfunction leading to reduced energy flowing to the brain is a primary cause. Together with hyper-glycosylation, the excessive build-up of sugar-based structures on proteins in the brain, disrupting brain signalling.
The researchers in this new study found excessive amounts of these sugar bonded protein molecules in the brains of Alzheimer’s brains – and more as the disease progressed.
This is powerful support for the need to control your blood sugar, adopt a Mediterranean style diet and take physical activity seriously.
Improving your metabolic health
The Mediterranean diet is ranked the number one way of eating for extending your health span – because it helps counteract all the 5 drivers of metabolic syndrome.
It is rich in fruits, vegetables, whole grains, lean proteins, and healthy fats like extra virgin olive oil. This means your diet has minimal highly processed foods. And it has high levels of both fibre and polyphenols – vital plant nutrients found largely in the vibrant colours of fruits, vegetables and herbs.
You need more nutrients as you get older
One of the lesser-known aspects of ageing is that you generally metabolise food less efficiently – as muscle mass decreases and you become more sedentary6.
This is at a time when it’s desirable to get higher levels of nutrients to counteract the drivers of illness and slow the ageing process itself.
That’s why new evidence supports the use of a daily vitamin and mineral pill for longevity7. And why a supplement to boost your intake of plant nutrients is also worth considering.
DailyColours is a new supplement containing over160 Mediterranean diet plant nutrients. In clinical trials at Kings College London and at the University of Exeter it produced significant improvements in cognitive and physical measures8.
Maintaining activity levels is essential
The Mediterranean diet is also the simplest way to maintain a healthy body weight because it is nutrient dense, not calorie dense like a typical Western diet. Therefore, it reduces the risk of all 5 markers of metabolic syndrome.
Maintaining your activity levels is equally important in preventing metabolic syndrome. And this must include a level of strength exercises. Because maintaining muscle is a vital way to maintain a normal metabolic rate and increase insulin sensitivity.
The simple activity regime you can get here, which includes wall squats, can be done in 7 minutes a day on 3 days a week.
Finally, ensuring 7-8 hours of sleep a day and taking specific action to reduce stress are important components of metabolic health. Which helps restore your energy, vitality and health, and supports longevity.
Part of a Series
This article is part of series on staying healthy as you get older and improving your quality of life.
It’s not only a goal almost everyone shares, but has huge implications on national healthcare spending, productivity and economic resilience.
It strongly recommends the Mediterranean diet as the best way of eating but recognises that maintaining strength and aerobic fitness is also a critical part of a healthy ageing lifestyle.
It also suggests a supplement to help reach the increased plant nutrient levels that you need as you get older.
DailyColours® contains 161 plant nutrients – nutrients that are missing from an ordinary vitamin and mineral pill. Clinical trials show that it offers Mediterranean diet benefits in a daily supplement. You can see it here.
Note: The content on this site is intended for general wellness and informational purposes only. It is not personalized medical advice. Consult a healthcare professional before making any changes to your diet, exercise, or lifestyle routines.
Author: Colin Rose
Colin Rose BSc is a health and longevity researcher and author with more than 30 years of experience researching healthy ageing, nutrition, and longevity. He is a Fellow of the Royal Society of Arts and a Senior Associate of the Royal Society of Medicine.