The plain-English calorie guide

1. Calories are energy

A calorie is just a unit of energy. Your body burns energy all day — to breathe, move, and digest — and gets energy from food. Whether you lose, gain, or maintain weight comes down to the balance between energy in (what you eat) and energy out (what you burn).

2. Your maintenance number (TDEE)

Your TDEE (Total Daily Energy Expenditure) is roughly how many calories you burn in a day. It's built from your BMR — the energy you'd burn at complete rest — multiplied by an activity factor. ZEUFIT estimates yours from your age, height, weight, sex, and activity level using the Mifflin–St Jeor equation.

3. Deficit to lose, surplus to gain

• Lose fat: eat a bit below your TDEE (a "deficit"). Around 7,700 kcal is roughly 1 kg of body fat, so a ~500 kcal daily deficit trends toward ~0.5 kg/week.
• Gain muscle: eat slightly above your TDEE (a "surplus") and train with resistance.
• Maintain: eat around your TDEE.

ZEUFIT sets a safe, sustainable target for your chosen pace — never crash-low.

4. Macros: protein, carbs, fat

• Protein (4 kcal/g): the most important macro when losing fat or building muscle. It keeps you full and protects lean mass. A common target is ~1.6–2.0 g per kg of bodyweight.
• Carbs (4 kcal/g): your body's main fuel, especially for training.
• Fat (9 kcal/g): essential for hormones and health — don't cut it too low.

Because protein and carbs are 4 kcal/g and fat is 9 kcal/g, your macros always add back up to your calories.

5. Fiber & the rest

Fiber (aim ~14 g per 1,000 kcal) keeps you full and supports digestion. Micronutrients matter for health, but for weight change, calories and protein do most of the heavy lifting.

6. Consistency beats perfection

You don't need a flawless day — you need a good average across the week. That's exactly what ZEUFIT is built to show you: log what you eat, watch your trend, and let the forecast keep you honest.

This guide is general educational information, not medical or dietary advice. Talk to a qualified professional before making significant changes, especially if you have a health condition.