Key takeaways
- Metabolism converts food into energy.
- Muscle mass and activity have the biggest controllable impact.
- Blood sugar balance affects energy and cravings.
- Sleep and stress influence metabolic hormones.
- Small daily habits add up.
"Slow metabolism" is often blamed for weight gain and low energy. But what is metabolism, really, and what can you do to support it? Here are the basics.
What is metabolism?
Energy in, energy out
Metabolism includes every process your body uses to break down food, produce energy and build and repair tissue. The calories you burn at rest, your basal metabolic rate, make up the largest share of daily energy use.
Cellular energy
Inside each cell, mitochondria convert nutrients into ATP, the body's energy currency. Nutrients like alpha lipoic acid play a part in this process.
Blood sugar balance
After a meal, insulin helps move glucose into cells. When this works smoothly, energy is steady; when it doesn't, spikes and crashes can drive fatigue and cravings.
What affects your metabolism?
| Factor | Effect |
|---|---|
| Muscle mass | More muscle burns more energy at rest |
| Age | Muscle and metabolic rate tend to decline |
| Activity | Movement increases daily energy use |
| Sleep | Short sleep disrupts appetite and insulin |
| Stress | Cortisol affects blood sugar and fat storage |
How to support a healthy metabolism
Strength train two to three times a week to build muscle. Move throughout the day, not just at the gym. Eat protein and fibre at every meal. Limit sugary drinks and ultra-processed foods. Sleep 7 to 9 hours and manage stress. Nutrients such as chromium, alpha lipoic acid and green tea are also studied for their roles in metabolism.
Sources
- Mayo Clinic – "Metabolism and weight loss: how you burn calories."
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) – "Insulin resistance and prediabetes."
- Harvard Health Publishing – "The truth about metabolism."
Common questions
What is metabolism?
Metabolism is the set of chemical processes that convert food into energy and build and repair the body.
Why does metabolism slow with age?
Muscle mass and activity often decline with age, which lowers the number of calories burned at rest.
How can I support my metabolism naturally?
Build muscle, stay active, eat protein and fibre, limit sugary drinks, sleep well and manage stress.