Losing weight doesn’t need to be complicated. If you want to drop 1kg each week, you need to create a calorie deficit of about 7,700 calories over seven days. That works out to roughly 1,100 calories less each day than your body burns.
This guide shows you exactly how to do it safely and effectively, based on what actually works according to fitness research and nutrition science.
What Is a Calorie Deficit and Why Does It Work?
A calorie deficit happens when you eat fewer calories than your body uses for energy. Your body then burns stored fat to make up the difference.
One kilogram of body fat contains approximately 7,700 calories. To lose that 1kg in a week, you need to create a total deficit of 7,700 calories across those seven days.
The science is straightforward. Research shows that weight loss comes down to energy balance. When you consistently burn more calories than you consume, your body taps into fat stores for fuel. This is how to lose 1kg a week calorie deficit works in practice.
How Many Calories Should You Eat Each Day?
Your daily calorie target depends on your current weight and activity level.
For a 90kg person who wants to lose 1kg per week:
- Maintenance calories: approximately 2,500 calories per day
- Weight loss target: 1,400 calories per day
- Daily deficit: 1,100 calories
For a 70kg person:
- Maintenance calories: approximately 2,200 calories per day
- Weight loss target: 1,100 calories per day
- Daily deficit: 1,100 calories
These numbers assume moderate activity levels. If you exercise more, you burn more calories and can eat slightly more while maintaining the same deficit.
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What Should You Actually Eat?
Focus on protein first. Aim for 0.8 to 1 gram of protein per kilogram of body weight each day. For a 75kg person, that’s 60 to 75 grams daily.
Protein keeps you full longer and helps maintain muscle mass while you lose fat. Studies show that people who eat higher protein diets lose more fat and less muscle compared to those eating lower protein amounts.
Your daily meals should include:
- Lean protein sources like chicken, fish, eggs, Greek yogurt, or legumes
- Vegetables that fill you up without many calories
- Whole grains in controlled portions for sustained energy
- Healthy fats in small amounts from sources like avocado, nuts, or olive oil
Cut back on processed foods high in sugar and refined carbs. These add calories without keeping you satisfied.
Should You Exercise or Just Diet?
Both work, but combining diet and exercise gives better results.
Research shows that diet alone produces meaningful weight loss. However, adding exercise helps you maintain muscle mass and improves your overall fitness.
A 30-minute walk burns roughly 150 to 200 calories. Do this daily and you’ve created an extra 1,050 to 1,400 calories of deficit per week. This means you can eat slightly more food while still hitting your weight loss target.
Strength training twice per week helps preserve muscle as you lose weight. This keeps your metabolism higher and improves your body composition.
How Do You Track Your Progress?
Weigh yourself once per week at the same time, preferably first thing in the morning. Your weight fluctuates daily due to water retention, food in your digestive system, and other factors.
Track your food intake using an app or food diary. Studies show that people who log their food consistently lose more weight than those who don’t track.
Take progress photos every two weeks. Sometimes the scale doesn’t move but your body composition changes. Photos capture what the scale misses.
What If You’re Not Losing Weight?
If you’re not losing 1kg per week after two weeks, your calorie deficit isn’t large enough.
Reduce your daily intake by another 200 calories or increase your activity to burn 200 more calories each day. Give it another two weeks and reassess.
Most people underestimate how much they eat by 20 to 30 percent. Measure your portions with a food scale for one week to get accurate numbers.
Is Losing 1kg Per Week Safe?
Yes, for most people. Health guidelines recommend losing 0.5 to 1kg per week as a safe and sustainable rate.
Losing weight faster than 1kg per week often means you’re losing muscle along with fat. This slows your metabolism and makes it harder to keep the weight off long term.
If you have less than 10kg to lose, aim for 0.5kg per week instead. Smaller bodies need smaller deficits.
How Much Does This Cost?
Losing weight through calorie reduction can actually save you money. You’re eating less food overall, which means lower grocery bills.
Basic healthy foods in Australia cost:
- Chicken breast: $12 to $15 per kg
- Eggs: $5 to $7 per dozen
- Frozen vegetables: $3 to $5 per kg
- Brown rice: $3 to $4 per kg
- Greek yogurt: $6 to $8 per kg
You don’t need expensive supplements or meal replacement shakes. Whole foods provide everything you need for healthy weight loss.
If you want professional guidance, personal trainers in Melbourne charge $60 to $100 per session. A nutritionist consultation costs $100 to $150 for the initial visit. These aren’t necessary but can help if you want extra support.
Frequently Asked Questions
How long will it take to lose 10kg?
At 1kg per week, you’ll lose 10kg in roughly 10 weeks. Some weeks you might lose more, some weeks less, but this gives you a realistic timeframe.
Can I eat whatever I want as long as I stay under my calorie limit?
Technically yes, but you’ll feel hungry and tired. Nutrient-dense whole foods keep you satisfied and energized. Save treats for occasional enjoyment rather than daily habits.
What if I have a bad day and overeat?
One day won’t ruin your progress. Get back on track the next day. Don’t try to compensate by eating very little. Just return to your normal calorie target.
Do I need to cut out carbs completely?
No. Carbs aren’t the enemy. Total calories matter most for weight loss. Include moderate amounts of whole grain carbs for energy and satisfaction.
Will I lose muscle along with fat?
You’ll maintain most of your muscle by eating enough protein and doing strength training twice per week. Some muscle loss is normal with any calorie deficit, but you can minimize it.
Should I eat less on rest days?
You can keep your calories consistent every day. This makes meal planning simpler and helps you build sustainable habits.
The key to losing 1kg per week is consistency. Create your calorie deficit through a combination of eating less and moving more. Track your intake honestly. Give your body time to respond. The results will follow.
