Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
We’ve all heard the saying: ‘Breakfast is the most important meal of the day.’ But is that really true, especially when it comes to weight loss?
Some people swear by a hearty morning meal to kickstart their metabolism, while others skip breakfast entirely and still manage to drop kilos. In fact, research shows that more than a quarter of adults skip breakfast, often in an attempt to cut calories or save time. At the same time, several observational studies have linked regular breakfast consumption to lower body mass index (BMI) and better appetite control throughout the day.
So what’s the deal?
In this blog, we’ll unpack the role breakfast plays in weight loss, explore what happens when you skip it, and highlight how a well-balanced morning meal can influence your energy, appetite, and eating habits throughout the day.
When you're trying to lose weight, what you eat and when you eat can make a real difference. Breakfast plays a key role in setting the tone for your day. After a night of fasting, your body needs fuel to kickstart your metabolism and maintain steady energy levels.
Eating a balanced breakfast may help you manage your appetite throughout the day. When you skip it, you're more likely to experience stronger cravings or overeat later, especially when you're tired or hungry. For some people, that can lead to mindless snacking or grabbing whatever's most convenient, even if it’s not the healthiest choice.
In fact, a randomised crossover trial found that women who ate a high-protein breakfast (30–39 grams of protein) experienced greater satiety and consumed fewer calories at lunch compared to those who ate a low-protein or no breakfast at all. It also helped stabilise their blood sugar and insulin levels post-meal, which are key factors in managing weight and energy.
Of course, everyone's body and routine are different. But for many, breakfast is more than just a meal—it’s a foundation for healthier habits.
You might think skipping breakfast saves time or cuts calories, but your body often tells a different story. Here's what really goes on when you miss your morning meal.
Skipping breakfast may seem like a simple way to cut calories, but it can actually lead to greater hunger later in the day. When you go too long without eating, your body produces more of the hunger hormone ghrelin, which can intensify your cravings, especially for quick, high-sugar or high-fat snacks.
According to research, people who skip breakfast often feel hungrier and end up eating more at their next meal, due to shifts in appetite-regulating hormones and how the body processes food. As a result, you're more likely to reach for whatever's convenient, not necessarily what's nutritious. This pattern often leads to overeating at lunch or dinner, making it harder to stay within your desired calorie range and stick to your weight loss goals.
Breakfast helps wake up your metabolism after an overnight fast. Skipping it can lead your system to conserve energy, which may slightly lower your metabolic rate over time.
Without morning fuel, your body also lacks the immediate energy it needs to function well, especially if your day starts off busy or physically demanding. A study has found that skipping breakfast can lead to lower energy and reduced physical activity in the morning, which may explain why many people feel sluggish, tired, or mentally foggy when they go without it. This drop in energy can affect both productivity and motivation to stay active throughout the day.
Food isn’t just fuel for your body—it’s also fuel for your brain. Skipping breakfast can lead to a drop in blood sugar levels, which may cause irritability, mood swings, and difficulty focusing.
In one study, researchers found that even one skipped breakfast can disrupt glucose regulation and lead to higher blood sugar spikes after later meals, which may impact both mental clarity and emotional balance. You might find yourself feeling anxious, impatient, or mentally ‘off’ by mid-morning. For people managing work, school, or parenting responsibilities, this dip in mental performance and emotional balance can make the day feel more stressful and harder to manage overall.
Eating breakfast isn’t a magic solution for weight loss, but it can definitely set the stage for healthier habits. These are some of the ways breakfast can support your weight loss efforts.
Research found that eating a high-protein breakfast can lead to greater feelings of fullness, improved appetite regulation, and even reduced evening snacking compared to skipping breakfast or eating a lower-protein meal. This satiety reduces the urge to snack on high-calorie foods between meals, making it easier to stay within your daily intake goals.
When you’re not constantly battling hunger, it becomes easier to stay focused on your nutrition plan and resist impulsive food choices. Plus, feeling satisfied early in the day can set a positive tone for more mindful eating throughout.
Eating in the morning kickstarts your metabolism after hours of fasting and helps your body use energy more efficiently throughout the day. A study comparing breakfast skipping and dinner skipping indicated that while skipping breakfast may slightly increase fat burning, it can also lead to higher blood sugar and insulin levels after lunch; this suggests that the body becomes less flexible in how it handles energy.
A steady metabolism, combined with balanced blood sugar levels, can improve fat-burning and reduce cravings triggered by energy dips. If your blood sugar remains stable, then you're less likely to experience mid-morning crashes or overeat later to compensate. This balance also supports better hormone regulation, which plays a key role in long-term weight management.
Starting your day with a filling breakfast can make it easier to control portions at lunch and dinner. It also helps you avoid the ‘hangry’ decisions that lead to quick, processed, or overly large meals later on.
Research indicates that people who eat a high-protein breakfast tend to feel more satisfied, have fewer food cravings, and are less likely to snack on high-fat or high-carb foods in the evening. They also show less brain activity in areas linked to food reward, which suggests better control over impulsive eating. Over time, this supports more consistent eating patterns that are key for sustainable weight loss.
Breakfast provides the fuel your body and brain need to function well in the morning. When you feel energised and mentally clear, you’re more likely to stay active and make choices that align with your health goals. Whether it’s going for a walk, getting through a workout, or simply being productive at work, that early energy gives you momentum. This increased movement throughout the day can make a meaningful difference in your overall energy expenditure.
A nutritious morning meal sets the tone for the rest of the day, helping you feel full, energised, and less likely to overeat later on. On the other hand, certain foods may seem convenient or satisfying at first, but can work against your goals by spiking blood sugar or adding unnecessary calories.
Here’s a quick guide to smart breakfast choices and what to skip:
Eggs: High in protein and nutrients, eggs help keep you full and support muscle repair.
Greek yoghurt: Rich in protein and probiotics, it promotes satiety and gut health.
Oatmeal: A great source of fibre and complex carbs that provide lasting energy.
Chia pudding: Packed with fibre, omega-3s, and antioxidants for long-lasting fullness.
Whole grain toast: A fibre-rich alternative to white bread that supports steady blood sugar.
Avocado: Full of healthy fats that promote fullness and nutrient absorption.
Fresh fruits: Naturally sweet, high in fibre, and loaded with vitamins.
Smoothies with protein: A quick, customisable option—just watch the sugar content.
Cottage cheese: High in protein and calcium, with a creamy texture that pairs well with fruit or nuts.
Nuts and seeds: Add healthy fats, protein, and crunch to your breakfast with small portions.
Sugary cereals: Often high in refined sugar and low in fibre, leading to crashes and cravings.
Pastries and doughnuts: High in sugar and unhealthy fats, with little nutritional value.
White bread: Lacks fibre and can spike blood sugar, leaving you hungry again soon after.
Flavoured yogurts with added sugar: These can contain more sugar than a dessert.
Pancakes with syrup: A sugary carb bomb that doesn’t keep you full for long.
Fried breakfast items: These tend to be high in calories and saturated fats.
Processed meat: Bacon and sausages are often high in sodium, preservatives, and saturated fat.
Sweetened coffee drinks: Loaded with sugar and empty calories that can sneak into your day unnoticed.
Breakfast can play a powerful role in supporting your weight loss journey, but it’s not just about whether you eat; it’s also about what you eat. Choosing nutrient-dense, balanced foods in the morning can help manage hunger, regulate energy levels, and set you up for better decisions throughout the day. While skipping breakfast may work for some, a thoughtful approach to your first meal can be a valuable part of a sustainable, healthy routine. Listen to your body, build habits that suit your lifestyle, and take small steps that move you toward your goals.
Want to know why breakfast matters for shedding pounds? Check out How?To?Increase?Your?Metabolism for a science-backed explanation on why starting your day with a solid breakfast boosts metabolism and supports weight-loss goals.
Dr Nick Fuller is the founder of Interval Weight Loss and is a leading obesity expert at the University of Sydney with a Ph.D. in Obesity Treatment. Dr Fuller is also the author of three best-selling books and his work been published in top ranked journals in the medical field, including JAMA, Lancet and American Journal of Clinical Nutrition.