⚡ Metabolism: How the Body Turns Food Into Energy
Understand enzymes, anabolism vs catabolism, hormones, and basal metabolic rate (BMR) in kids.
What Is Metabolism?
Metabolism (meh-TAB-uh-liz-um) is the chemical reactions in the body's cells that change food into energy. Our bodies need this energy to do everything — from moving to thinking to growing. Specific proteins (enzymes) control these reactions. Thousands of metabolic reactions happen at the same time to keep cells healthy and working.
How Does Metabolism Work?
After we eat, the digestive system uses enzymes to break down food into building blocks the body can use: proteins into amino acids, fats into fatty acids, and carbohydrates into simple sugars (like glucose). These are absorbed into the blood and carried to cells where more enzymes either release their energy or store it.
Anabolism
Builds and stores: supports growth, tissue maintenance, and energy storage.
Catabolism
Breaks down molecules to release energy for movement, heat, and cell work.
Waste Removal
Waste leaves via skin, kidneys, lungs, and intestines.
What Controls Metabolism?
Hormones from the endocrine system guide the rate and direction of metabolism. Thyroxine (from the thyroid) sets the overall pace. The pancreas releases insulin in response to rising blood glucose after meals, signaling cells to build and store (anabolism). Other hormones also influence energy use and storage.
Thyroid Hormone (Thyroxine)
Helps determine how fast or slow metabolic reactions occur.
Pancreas and Insulin
Promotes storage and use of glucose, shifting the balance toward anabolism after meals.
Basal Metabolic Rate (BMR)
BMR is how many calories the body burns at rest. It’s affected by genetics, health, age, and body composition. Kids with more muscle and less fat generally have higher BMRs. Exercise can improve fitness and increase BMR.
- • Higher muscle mass tends to raise BMR
- • Some medical conditions and medications affect BMR
- • Consistent physical activity supports a healthier BMR
Healthy Habits for Kids
Daily Basics
- • Balanced meals with fruits, veggies, whole grains, and protein
- • Regular physical activity
- • Adequate sleep for age
- • Limit sugary drinks and ultra-processed snacks
When to Check With a Doctor
- • Unexplained weight changes or fatigue
- • Concerns about growth or delayed puberty
- • Family history of thyroid or metabolic conditions
Frequently Asked Questions
❓ Can kids change their metabolism?
Yes. Regular exercise builds muscle and can raise BMR. Good sleep and balanced nutrition also help.
❓ What’s the role of the thyroid?
Thyroxine from the thyroid helps set the pace of metabolism throughout the body.
❓ Why do some kids gain weight more easily?
Differences in BMR, body composition, activity, and diet all play a role; genetics and health conditions matter too.
📝Key Takeaways About Metabolism
- ✓Metabolism includes anabolism (building) and catabolism (breaking down).
- ✓Hormones like thyroxine and insulin guide energy use and storage.
- ✓BMR varies by muscle mass, genetics, and health — and activity can help.
- ✓Healthy habits support balanced metabolism in growing kids.
⚠️Medical Disclaimer
The information provided on this page about metabolism, energy balance, hormones, and related health topics is for educational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Every child is unique, and metabolic concerns require individual assessment by qualified healthcare professionals.
Always consult with your child's pediatrician or qualified healthcare provider if you have concerns about weight changes, fatigue, growth, or other symptoms. For medical emergencies, call 911 or visit your nearest emergency room immediately. Content compiled from trusted pediatric health references and medically reviewed educational resources.