«I have a slow metabolism» is one of the most common phrases we hear at the office. But what is metabolismin practice, what affects it and what can we really do about it? In this guide you will see the basics, what holds true for age, 7 everyday habits that support it and how you can measure it instead of guessing.
What metabolism is
Metabolism is the sum of the processes by which the body converts food into energy. When we talk about a «fast» or «slow» metabolism, we usually mean how many calories the body burns during the day.
The largest part is basal metabolism or resting metabolism: the energy the body needs at rest for its vital functions, such as heart function, breathing and maintaining body temperature.
Where the day’s calories «go»
| Component | What it is |
|---|---|
| Resting metabolism | The calories you burn at complete rest. It accounts for 60–75% of the energy we use every day. |
| Thermic effect of food | The energy needed to digest and use food. It is about 10% of daily expenditure and is higher for protein. |
| Movement and exercise | Whatever is left: exercise, walking, chores, even standing. It is the part that varies most from person to person. |
What affects metabolism
- Body size: heavier and taller people have a higher metabolism.
- Muscle mass: the fitter we are, the higher our metabolism, mainly because of greater muscle mass.
- Sex and age.
- State of health: e.g. medication or health problems, such as thyroid disorders.
Does metabolism drop with age?
Less than we think. In a large study published in the journal Science (2021), with data from more than 6,000 people, metabolism, after taking body size and muscle mass into account, remained almost stable from age 20 to 60 and began to decline after 60.
Put simply: the kilos that «creep up» after 30 or 40 are more often linked to less movement, loss of muscle mass and changes in habits, and less to a metabolism that has «got stuck».
Can metabolism be «activated»?
There is no food or drink that «unlocks» metabolism. But there are habits that help the body maintain its muscle mass and spend more energy during the day.
7 habits that support metabolism
1. Resistance training
Weights, bands or bodyweight exercises 2–3 times a week help maintain and increase muscle mass.
2. More movement during the day
Stairs instead of the lift, walking for short trips, standing while on the phone. Small movements add up.
3. Protein at every meal
Eggs, yoghurt, pulses, fish, chicken. Protein has the greatest thermic effect of all macronutrients and also helps satiety.
4. No very strict diets
Very low calories for a long time can lead to loss of muscle mass. A balanced programme, adapted to your own needs, is more effective in the long term.
5. Enough sleep
Too little sleep affects appetite, energy for movement and our food choices.
6. Regular, balanced meals
Small, frequent meals, as in our weekly menu, help you avoid arriving at the next meal starving.
7. Measuring instead of guessing
The equations that calculate metabolism give an estimate. Measurement shows what is true for your own body.
How metabolism is measured
The measurement is done at rest, breathing calmly through a special mask. At our office it is done in two ways:
| Measurement | What’s included |
|---|---|
| PNOĒ metabolic measurement Thessaloniki · €80 |
About 10 minutes. Resting metabolic rate, calories for weight loss, maintenance or gain, how much fat and how many carbohydrates you «burn», metabolic flexibility, respiratory indicators and heart rate variability. |
| Basal metabolic rate RMR measurement (Fitmate) Drama · €60 |
Less than 15 minutes. It shows the calories you burn at rest, so that your nutrition programme is based on your real needs. |
The measurement is particularly useful at the first visit, during a nutrition effort, and for those who gain weight easily while following their programme. It is often combined with body fat measurement, so that muscle mass is shown too.
What about supplements?
No supplement «boosts» metabolism on its own. But some nutrients play a role in energy metabolism:
| Product | What it contains |
|---|---|
| Active Woman My Metavolismos | 18 ingredients, including B vitamins, iron, zinc and chromium. Vitamins B2, B3, B5, B6, B12 and iron contribute to the reduction of tiredness and fatigue and to normal energy-yielding metabolism. |
| Metabolism Support pack | My Metavolismos, Xtra Weight Loss and Water Away. Glucomannan, in the context of an energy-restricted diet, contributes to weight loss, with a daily intake of 3 g. |
Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle.
Frequently asked questions
How many calories do I burn at rest?
It depends on your body, muscle mass, sex and age. The exact number comes from a resting metabolism measurement.
Are there foods that «burn» calories?
Not in a way that makes a difference to weight. Protein needs more energy to be used, but the big picture is overall diet and movement.
Does metabolism decrease after 40?
According to the 2021 study in Science, metabolism stays almost stable until 60 when muscle mass is taken into account. That is why maintaining muscle matters so much.
I have a thyroid problem. Does the measurement make sense?
Yes, in cooperation with your treating doctor. The measurement helps adapt the nutrition programme to your real needs.
Do genes play a role?
Some tendencies, e.g. for carbohydrates and fats, can be seen in the nutrition DNA test. But lifestyle remains the main factor.
Can I book an appointment online?
The measurement is done at the office. The discussion of the results and the nutrition programme can also be done by online appointment.
Sources
- Pontzer H. et al. Daily energy expenditure through the human life course. Science, 2021.
- Diet induced thermogenesis, older and newer data with emphasis on obesity and diabetes mellitus – A narrative review.
This article is for information purposes and is not a medical diagnosis, nor does it replace a doctor’s advice.