🔍 Introduction
Energy balance is the physiological foundation of any body composition change.
Simply put: if you consume more energy than you expend, you gain weight; if you consume less, you lose weight.
It might sound obvious, but understanding and applying this principle correctly is what separates sustainable progress from endless cycles of frustration.
⚙️ What is energy balance?
Your body uses energy (calories) for three main functions:
Basal metabolism: maintaining vital processes like breathing, temperature, and cellular function.
Physical activity: from training to walking or moving throughout the day.
Thermic effect of food: energy used to digest and process what you eat.
The balance between energy intake (in) and energy expenditure (out) determines your energy state:
🔺 Caloric surplus: you consume more energy → weight gain (ideal for muscle growth).
🔻 Caloric deficit: you consume less energy → weight loss (ideal for fat reduction).
⚖️ Maintenance: energy intake and expenditure are equal → stable weight.
📊 How to find your maintenance calories
🔹 Practical method (recommended)
For two weeks, track your daily calorie intake and body weight:
If your weight stays stable → you’re at maintenance.
If it increases → you’re in a surplus.
If it decreases → you’re in a deficit.
This gives you a personalized and far more accurate reference than any formula.
🔹 Estimated method (by calculation)
You can estimate your maintenance calories by multiplying your body weight (in kilograms) by a range between 30 and 35, depending on your activity level:
Sedentary: ×30
Moderately active: ×32–33
Very active: ×34–35 or more
Then adjust your calories based on weekly progress:
- if your weight stays stable, you’re at maintenance;
- if it increases or decreases, adjust accordingly.
⚡ Deficit and surplus: how much and how fast
The size of your deficit or surplus depends on your goal and experience level.
🔻 For fat loss:
Beginner or higher body fat: 0.5–1% of body weight per week.
Intermediate or advanced: 0.25–0.5% per week.
Larger deficits can accelerate fat loss but also increase fatigue, reduce performance, and risk muscle loss.
🔺 For muscle gain:
Beginner: 1–1.5% of body weight per month.
Intermediate: 0.5–1% per month.
Advanced: 0.25–0.5% per month.
A surplus that’s too high won’t speed up muscle growth, it’ll just increase fat gain.
🧠 The role of metabolism and adaptation
Your body isn’t a calculator. Over time, it adapts to energy changes:
In a deficit, it reduces expenditure to conserve energy.
In a surplus, it increases expenditure through more spontaneous movement and thermogenesis.
That’s why formulas are only starting points, consistent monitoring and gradual adjustments are essential.
💡 Energy availability and health
Energy availability refers to how much energy remains for physiological functions after subtracting what’s used for training.
For men: maintain at least 25 kcal/kg of lean body mass.
For women: maintain at least 30 kcal/kg of lean body mass.
Lower levels can lead to:
Hormonal disruption.
Chronic fatigue.
Decreased performance.
Loss of menstruation in women or low libido in men.
The goal isn’t just to stay lean, it’s to maintain enough energy to perform, recover, and stay healthy.
💬 Conclusion
Managing your energy is the first real step toward any physical goal.
Calories aren’t everything, but without proper energy balance, nothing else works.
Smart planning means knowing your starting point, adjusting gradually, and listening to your body’s feedback.
“You can train perfectly and eat clean, but if you don’t control your energy intake, you won’t control your results.”