Metabolism is the sum of all chemical reactions in the body that convert food into energy and build or break down tissues. It determines how quickly your body burns calories and is central to weight management and overall health.
Metabolism refers to all the biochemical processes occurring in the body's cells to maintain life — converting food and oxygen into energy, building and repairing tissues, eliminating waste products, and regulating body temperature. It is divided into two main processes: catabolism (breaking down molecules to release energy, such as digesting food) and anabolism (building molecules, such as building muscle protein).
Basal Metabolic Rate (BMR) is the number of calories the body burns at complete rest just to maintain vital functions — breathing, circulation, cell repair, and temperature regulation. BMR accounts for 60–70% of total daily calorie expenditure and is influenced by age, sex, body composition, genetics, and thyroid hormone levels. People with more muscle mass have a higher BMR because muscle burns more calories than fat even at rest.
In Korea, understanding metabolism is increasingly relevant given rising rates of obesity, type 2 diabetes, and metabolic syndrome, particularly as diets shift toward more processed and Westernised food. Metabolic syndrome — a cluster of conditions including abdominal obesity, high blood pressure, elevated blood glucose, and abnormal cholesterol — significantly increases the risk of heart disease and diabetes. Endocrinologists in Korea treat metabolic disorders including hypothyroidism (underactive thyroid that slows metabolism), and dietitians provide guidance on optimising metabolic health through evidence-based nutrition and exercise.
Key Points
- Metabolism = all chemical processes converting food to energy and maintaining body functions
- Basal Metabolic Rate (BMR) is calories burned at rest — 60–70% of daily energy use
- Muscle mass increases BMR — resistance training supports metabolic health
- Thyroid hormones are the primary regulators of metabolic rate
- Metabolic syndrome (obesity + hypertension + high glucose + abnormal cholesterol) is increasingly common in Korea
- Age, genetics, hormones, and body composition all influence metabolic rate
When to See a Doctor
- Unexplained weight gain or difficulty losing weight despite diet and exercise
- Persistent fatigue, cold intolerance, or dry skin — may indicate underactive thyroid
- Unexplained weight loss with increased appetite — may indicate overactive thyroid or diabetes
- Diagnosis of metabolic syndrome — requires management by a doctor or endocrinologist
For emergencies in Korea, call 119
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This content is published for educational purposes only. For accurate diagnosis and personalised treatment, consult a licensed KMA physician in Korea.
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This article is published by DoctorsInKorea.com for educational and informational purposes only. It does not replace a professional clinical evaluation by a licensed healthcare provider. For accurate medical diagnosis and personalised treatment paths, please book an appointment with a licensed KMA physician. For immediate life-threatening medical emergencies in Korea, please call 119.
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Last reviewed: March 1, 2025