The Science of Metabolism: Why It's Not Just About Calories

If you've been tracking calories, cutting portions, and still wondering why the scale won't budge, you're not alone. In Dubai's fast-paced, calorie-rich environment, many residents experience confusion about weight, energy and the role of metabolism. This article explains the science behind metabolism, dispels common myths, and offers practical steps - while reminding you it's always best to consult a healthcare professional for a diagnosis. Our doctors at Zaincura can provide a personalized assessment.

Is weight loss purely about calories?

Short answer: No - but calories matter. Weight change ultimately reflects energy balance (calories in vs. calories out), yet that simplification misses important biology and behaviour.

• Energy balance is the underlying principle: to lose weight you generally need to consume fewer calories than you expend over time.
• However, how your body processes food, hormonal regulation (insulin, leptin, thyroid hormones), body composition (muscle vs. fat), genetics, sleep, stress and medications all influence appetite, energy expenditure and where weight is lost or retained.

In practical terms for Dubai residents: two people eating the same calories can have different outcomes due to muscle mass, activity types (walking city vs. gym workouts), heat-related changes in activity, or conditions like hypothyroidism. So calories are necessary to consider, but they are not a complete explanation.

What is the science behind metabolism?

Metabolism refers to all chemical reactions in the body that maintain life. For weight and energy, the key components are:

• Basal Metabolic Rate (BMR): energy used at rest for breathing, circulation and cellular processes — influenced by age, sex, genetics and lean body mass.
• Thermic Effect of Food (TEF): energy used to digest and process food (higher for protein).
• Physical activity: deliberate exercise plus non-exercise activity thermogenesis (NEAT) - daily movements, fidgeting, walking in the city, shopping in malls, etc.
• Adaptive thermogenesis: metabolic adjustments when you lose weight or change calorie intake (the body can reduce energy expenditure to conserve fuel).

Other biological factors:

• Hormones (thyroid, insulin, cortisol) regulate appetite and how energy is stored or burned.
• Muscle mass burns more calories at rest than fat, so resistance training raises BMR modestly.
• Age and sex: metabolism typically slows with age and differs between men and women due to body composition.
• Gut microbiome and genetics also play a role, though research is ongoing.

Sources like the Mayo Clinic and NHS explain these components and how they interact to influence weight and energy.

Is 70% diet and 30% exercise true?

The "70% diet, 30% exercise" rule is a popular shorthand to emphasize that diet often has a bigger immediate effect on weight loss than exercise alone. It is not a scientific law.

• Diet influences the calories you consume. Reducing excess calories is usually the fastest way to create an energy deficit.
• Exercise increases calories burned, preserves/increases muscle mass, improves insulin sensitivity, mood and cardiovascular health. Over time, exercise helps maintain weight loss and improve body composition.

A more accurate view: both diet and exercise are essential but serve different roles. Diet primarily controls caloric intake; exercise supports long-term weight management, metabolic health and overall wellbeing. For sustainable results — particularly in Dubai where lifestyle and social eating are common — combine a sensible diet with strength training, aerobic activity and increased daily movement.

Why am I eating 1500 calories and not losing weight?

If you're consistently tracking ~1500 kcal/day and not losing weight, consider these common explanations:

1. Underestimating intake: portion sizes, hidden calories (sauces, drinks, restaurant items) and inaccurate food labels add up.
2. Overestimating burn: fitness trackers estimate energy expenditure and can be off; short, intense exercise can raise hunger leading to extra intake.
3. Inaccurate calorie goals: 1500 kcal may be appropriate for some but too high for others, depending on BMR and activity level.
4. Adaptive metabolic changes: weight loss can lower BMR and appetite signals, slowing progress.
5. Loss of muscle mass: if calories are reduced without resistance training, some weight loss can be muscle, which lowers BMR.
6. Medical issues: thyroid disorders, polycystic ovary syndrome (PCOS), certain medications (steroids, some antidepressants), and fluid retention can affect weight.
7. Timing and consistency: short-term plateaus are normal; consistent habits over weeks matter more than day-to-day changes.

Practical steps: track food more precisely for 1–2 weeks, ensure adequate protein and resistance training, check portion sizes, monitor liquid calories, and reassess resting metabolic needs. It's always best to consult a healthcare professional for a diagnosis if you suspect a medical cause.

When to Visit a Doctor at Zaincura

Book an appointment at Zaincura if:

• You have unexplained weight gain or loss despite consistent diet and activity changes.
• You experience symptoms of a hormonal problem (fatigue, cold intolerance, irregular periods, hair loss).
• You're on medications that may affect weight, or have chronic conditions like diabetes or heart disease.
• You want a personalised plan that considers blood tests (thyroid, fasting glucose, lipids), body composition, and lifestyle factors common in Dubai (shift work, fasting during Ramadan, heat-related activity changes).

Our doctors at Zaincura can provide a personalized assessment, order relevant tests, and create a realistic, culturally appropriate plan for nutrition, physical activity and follow-up. It's always best to consult a healthcare professional for a diagnosis.

Conclusion

Metabolism is complex: calories are important, but they interact with hormones, body composition, genetics and behaviour. For residents of Dubai navigating busy schedules and diverse food environments, a balanced approach that includes accurate tracking, resistance training, adequate protein, sleep and stress management offers the best chance for sustainable change. If progress stalls or symptoms suggest a medical issue, our team at Zaincura can help with testing and tailored care.

References

• Mayo Clinic — "Weight loss: 6 strategies for success". https://www.mayoclinic.org
• NHS — "Why am I not losing weight?". https://www.nhs.uk
• Centers for Disease Control and Prevention (CDC) — "Healthy Weight". https://www.cdc.gov/healthyweight
• World Health Organization (WHO) — "Obesity and overweight". https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
• Review on adaptive thermogenesis and weight loss, PubMed (e.g., Hall KD, et al.). https://pubmed.ncbi.nlm.nih.gov

For a personalised assessment or to book an appointment at Zaincura, contact our clinic - our doctors can guide testing and create a plan suited to your lifestyle in Dubai.