Here’s the lowdown on fat loss—covering all the essential points that professionals often forget to mention or assume you already know. Key insights like whether calories really matter for weight loss are discussed, as well as the role of exercise, sleep, hormones, and hunger cues.

In case you didn’t know

This part might be a refresher for some, but let’s start with the basic principles. The only way to lose weight is to consume fewer calories than you burn. You’ve probably heard of this before—it’s often referred to as ‘calories in vs. calories out.’

Each day, your body burns a specific number of calories, which can be calculated using various equations. The total number of calories your body utilises daily is referred to as your maintenance caloric needs—the amount required to sustain your weight. This includes energy needed to support your organs, bones, skin, fat, and muscle.  The number of calories per day varies significantly between different people and is based on factors like age, gender, height, activity level, and metabolism. There are many calorie calculators available and you can find my favourite one here.

In my practice, I find that most women require between 900 and 1,800 calories per day to lose weight, while men typically need between 1,500 and 2,500 calories, depending on their metabolism and exercise routine.

Ready to take control of your weight loss journey? Contact Julia for personalised nutrition advice and sustainable strategies to achieve your goals.

Fat loss tips

Therefore, to lose weight you need to consume fewer calories than you burn each day. To achieve this, you have four main options:

• Exercise more
• Exercise harder
• Eat less
• Eat healthier

Each of these options influences the balance between the calories you consume and the calories you burn, creating what’s known as a negative calorie balance.

In theory, it sounds simple. In practice, it’s much more challenging.

The three biggest factors that complicate fat loss:

• Stress
• Sleep
• Hormones

When I say hormones, I am specifically mentioning:

• Cortisol: Released due to stress
• Blood Sugar: Whether it’s regulated
• Testosterone: Low levels in men
• Estrogen: High levels in men or women
• Ghrelin: The hormone that makes us feel hungry

At the end of the day, stress, sleep, and hormones influence how many calories your body burns and how much it makes you consume by affecting hunger levels. Ultimately, it still ties back to the principle of calories in versus calories out.

Stay tuned for another blog, where I’ll dive deeper into how hormones affect weight loss and what you can do to manage them. This is especially important for people who sleep less than 8 hours, are burnt out at work, have PCOS, or are menopausal.

How to lose weight

The key to losing fat is creating a calorie deficit—consuming fewer calories than your body burns. This allows your body to tap into its long-term fat stores for energy. In simple terms, at the end of the week, you need to have consumed fewer calories than the total calories you burn through exercise and daily activities.

For sustainable fat loss, it’s recommended to reduce your calorie intake by 10–30% of your current consumption. Dropping calories too quickly can lead to negative side effects, including:

• Fatigue
• Irritability
• Loss of hunger cues
• Difficulty sleeping
• Headaches
• Feeling cold

These side effects are common when calorie intake is restricted too aggressively, impacting physical, mental, and emotional well-being.

Why calorie counting only mostly works

However, weight loss isn’t as simple as counting calories. Research shows that even nutritional professionals often miscalculate food intake by up to 30%. This happens because estimating portion sizes is challenging unless you weigh and measure everything you eat.

It’s particularly difficult to measure calories from foods prepared at restaurants, cafes, or cafeterias. Without precise ingredient lists or portion details, your calorie count will always be an estimate. Take this into account and use food tracking tools as a guide, not an exact science.

Why having an active lifestyle helps

It’s important to note that accurately estimating how many calories we burn each day is nearly impossible. This is because calculators don’t account for the natural variations in day-to-day activities, which can make precise measurements tricky—especially if you have a physically demanding job, walk to work, or engage in unpredictable levels of physical activity throughout the day.

Daily caloric expenditure naturally fluctuates, making it challenging to determine an exact balance of calories in versus calories out. Many factors can influence this, including:

• A sedentary day spent watching TV will burn far fewer calories than a night out dancing and partying
• Active weekends where you’re on your feet differ significantly from relaxed weekends
• Some days you go to work; other days you don’t
• Some days you exercise, while on others you rest
• Sleep patterns—sleeping in means you spend less hours awake burning calories
• Eating a diet high in fibre and protein can leave you feeling more full, which decreases hunger levels between meals
• Stress can impact insulin, causing sugar crashes that make you feel hungrier than usual
• Lack of sleep similarly disrupts insulin, leading to sugar crashes and increased hunger
• Hormonal fluctuations throughout the month can affect natural hunger cues too

Ultimately, caloric intake and expenditure are estimates, but tracking these numbers can help identify patterns and enable changes for better results.

If you’re interested in learning more, this article provides an excellent summary: Calories In, Calories Out – What You Need to Know.