Why Am I Not Losing Weight? 12 Possible Reasons

You want to lose weight. You are eating “cleaner” and exercising regularly. Yet nothing happens, or even worse, you gain weight.

For many Australians, this is not a matter of willpower. It’s a matter of physiology. Weight loss is a complex game involving hormones, inflammation levels, gut function, your sleep routine, and metabolism. The number of overweight people is rising globally, increasing the risk of health problems associated with excess weight.

Introduction to Weight Loss

Embarking on a weight loss plan is about more than just seeing the number on the scale go down. It’s about building healthy habits that support your overall health for the long term. To lose weight effectively, it’s important to understand the basics. That is, creating a calorie deficit, eating healthy foods, and incorporating regular exercise into your routine. Aiming for a healthy weight loss of about 0.5 to 1kg per week is both realistic and sustainable, helping you avoid the pitfalls of crash diets and rebound weight gain.

Focusing on a healthy weight isn’t just about appearance; it’s about reducing your risk of serious health problems. Modest weight loss can lower your risk of heart disease and improve your overall health. Remember, the goal is to lose weight in a way that supports your body, your energy levels, and your long-term wellbeing.

Here are 12 biologically based reasons for trouble losing weight. The good news is that you can address them with some understanding of the physiology involved.

1. Adaptive Thermogenesis: Your Metabolism Has Adapted

Eating too few calories for too long causes adaptive thermogenesis. Your resting metabolic rate (the number of calories you burn at rest) drops. You become metabolically efficient at burning low levels of calories. In this state, your body is in survival mode and fat loss is low on the priority list. Even when you are consuming fewer calories, your body may slow weight loss as a natural response to prolonged calorie restriction.

Then the dreaded weight loss plateau and subsequent rebound weight gain hit, even if you increase calorie intake by a small amount. This can also be affected by calorie creep, where people often overestimate the calories they burn and underestimate how much they actually eat, which can hinder progress.

2. Insulin Resistance is Keeping Fat Out of Reach

If your insulin levels are elevated most of the time, your body is biochemically stuck in storage mode. Insulin resistance:

• Promotes fat storage (especially visceral or abdominal fat).
• Blocks lipolysis (the burning of stored fat).
• Creates strong cravings for sugar and causes energy crashes.

Insulin resistance often leads to high blood sugar, which is a common complication associated with obesity and metabolic disorders. It can also make it more challenging to lose weight even when following good dietary habits. This medical condition is common in many Australians with a family history of Type 2 Diabetes or Metabolic Syndrome. Advanced metabolic blood panels can help detect insulin resistance.

3. Nutrient Density: You’re Missing Some Key Nutrients

Weight-loss diets often focus on what you should stop eating, instead of what to include in your diet. For instance, too little protein will result in the loss of muscle mass. Because muscle is metabolically active tissue, having less muscle results in less fat burning at rest. It also makes you less satisfied with the meals you consume. Adequate protein intake can help regulate appetite hormones, reducing feelings of hunger and supporting weight loss. In addition, you need fibre. Low fibre intake can disrupt the gut microbiome and create spikes in glucose levels after eating rather than gradual absorption.

4. The Cardio Only Approach to Exercise

Walking and cycling are great for cardio, but relying solely on cardio without incorporating strength training can limit your results. It is not the best approach to avoiding muscle loss during weight loss. Lifting weights or using resistance bands are forms of resistance training that help maintain lean muscle tissue. Inadequate strength training can hinder weight loss, as muscle burns more calories than fat. A body composition analysis helps you know what to work on to create a well-structured exercise plan. Otherwise, you might reach a state where your body fat percentage remains high even with low readings on the scales.

5. Over-Exercising Without Recovering

While exercising regularly is important for weight loss, over-exercising without adequate recovery can be counterproductive. With the “smashing it” attitude, it is easy to go overboard on HIIT (High Intensity Interval Training). Training too hard without enough recovery time can have negative effects, spiking cortisol levels, the body’s main stress hormone. Chronic levels of cortisol can increase abdominal fat levels and cause the breakdown of muscle tissue. Regular exercise, when combined with a balanced diet, is more effective for weight loss than exercise or diet alone.

6. Poor Sleep Quality and Sleep Apnoea

Sleep is one of the four critical pillars to manage for successful weight loss. The importance of quality sleep, not just duration, cannot be overstated for weight management. Poor sleep can increase the hunger hormone (ghrelin) and reduce the satiety hormone (leptin).

Obstructive sleep apnoea (OSA) is also common in Australia. It deprives your body of oxygen while you sleep, stressing your system. Snoring or waking up feeling unrefreshed may affect your metabolic rate, rather than helping your body recover from fatigue. Maintaining a consistent sleep schedule is essential to improve sleep quality and regulate hunger-related hormones.

7. Chronic Physiological Stress

Mental health plays a crucial role in managing stress and supporting weight loss. Stress is not just a feeling; it is a physiological state that can influence how your body processes blood glucose. Stress causes your liver to release extra glucose even when you have not eaten anything. If your body feels it is under constant threat from work, finances, or internal psychological processes, it may hold on to stores of energy (fat) as a protective mechanism. Stress can produce excess levels of cortisol, which shifts metabolism to store fat and increases appetite.

8. Undiagnosed Hormonal Imbalances

A comprehensive hormonal screening can detect several medical conditions which make weight loss difficult without clinical intervention:

• Hypothyroidism: When the thyroid gland is underactive and slows down metabolic processes. This can cause unintentional weight gain and exhaustion.
• PCOS: Polycystic ovarian syndrome affects 1 in 10 Australian women and is associated with significant insulin resistance. This condition signals your body to store fat while increasing hunger.
• Perimenopause/Menopause: Dropping levels of oestrogen change where your body stores fat, shifting distribution toward the abdomen.

9. Chronic Low-Grade Inflammation

Chronic inflammation is usually invisible. It may be caused by poor gut health, highly processed foods, or undiagnosed food sensitivities such as gluten or lactose. Consuming fast food can also promote inflammation, making weight loss more difficult. Chronic low-grade inflammation disrupts signalling between your fat cells and brain, which can lower the rate of fat loss.

10. The Gut Microbiome

Your gut microbiome influences how many calories you extract from food. If you have gut dysbiosis (an imbalance in the species of bacteria), you may be extracting more energy from the food you eat and creating chronic low-grade inflammation. If you struggle with bloating and digestion on a regular basis, gut health may explain why you don’t lose weight, even when you change your lifestyle.

11. Medication Side Effects

Certain medications, including many commonly used prescription drugs in Australia, can have weight-promoting side effects. For instance, some antidepressants, corticosteroids (prednisone), beta blockers for hypertension, and certain contraceptive pills or Menopause Hormone Therapy (MHT) may affect your weight loss goals. If you suspect that certain medications might be affecting your ability to lose weight, it is best to address this with your GP rather than stopping treatment.

12. Guessing Instead of Testing

The most common reason for weight loss failure is flying blind. Only relying on bathroom scales for feedback does not measure your body composition or fat versus lean tissue mass. Building muscle while losing fat can lead to no change in scale weight, but improved body composition. It is also common for the scale not to budge for a few days or weeks, which does not necessarily mean that fat loss is not occurring. Not measuring metabolic parameters like blood sugar levels (HbA1c), fasting insulin, lipid profiles, and inflammatory markers (hs-CRP) is treating symptoms rather than the underlying cause.

How to Promote Weight Loss

Besides understanding the "why," these strategies can help promote weight loss:

• Hydration: Drinking plain water instead of sugary drinks or sugar-free beverages supports metabolic function.
• Mindful Eating: This can help you feel fuller sooner and promote long-term weight loss. Do not skip meals; instead, portion your food to curb constant hunger pangs.
• Clinical Nutrition: Reducing refined carbs has been shown to help with weight loss for some people. Focus on whole foods and healthy snacks like nuts or fruit.
• NEAT: Physical inactivity lowers non-exercise activity thermogenesis (NEAT), which can significantly reduce total daily energy expenditure.

Weight Loss Is More Personal Than You Think

Weight loss does not have to be an uphill battle. When you understand what is affecting your weight challenge and support those systems, losing weight becomes a more sustainable outcome of getting healthier. At Everlab, we view weight challenges as health challenges. We use advanced and accessible tests, combined with clinical expertise, to give you actionable insights into what is going on in your body.

Overcoming Plateaus

If you’ve been following your weight loss plan and suddenly hit a weight loss plateau, you’re not alone. Plateaus are a normal part of the process. The key is to reassess and make small, strategic changes. Try increasing your physical activity and ensure you are incorporating enough whole foods to keep you satisfied. Getting enough sleep is also crucial, as poor sleep can slow your metabolism and make it harder to lose weight.

Sources

1. ‍Weight loss - a healthy approach- Victoria State Government
2. ‍Dieting and weight management- Queensland Government
3. ‍About overweight and obesity- Australian Government
4. ‍Weight loss and dieting- Australian Government