Understanding Metabolism: 7 Things That Help and Hinder Your Metabolic Health

Metabolism refers to all the essential chemical processes that occur within your body to keep you alive and functioning — including converting food into energy, regulating hormones, maintaining body temperature, and supporting cellular repair.

Think of your metabolism like a fire — one that needs to burn steadily and efficiently to keep your body’s engine running smoothly.

When that metabolic fire is burning bright, it provides us with stable energy, good digestion, effective repair and recovery, balanced hormones, and supports a healthy weight. But when that fire burns low — or becomes sluggish — we may start to experience symptoms like fatigue, poor digestion, hormone imbalances, and weight gain.

What Influences our Metabolism?

When someone says they have a slow metabolism, it typically means one's body burns fewer calories at rest and during activity. A fast metabolism, means their body burns energy more quickly. Think of children and teenagers who seem to have endless energy as their metabolic rate is naturally higher than that of adults. Metabolic rate is highest in our youth, stabilises in adulthood, and gradually declines from age 60 (7).

Several key factors influence your metabolic rate, including:

• Age

• Gender (men generally have a higher metabolic rate than women)

• Genetics

• Muscle mass

• Hormones

• Food intake and nutrient quality

• Stress levels

• Sleep quality

• Daily movement and activity levels

In women, menopause can bring about a drop in metabolic rate of up to 15%, which is largely due to declining oestrogen levels and a reduction in lean muscle mass (2).

While we can’t control certain factors like genetics, gender, or ageing, the good news is, that there are ways that we can support and boost our metabolism, as well as habits to avoid which slow it down.

Things That Hinder Metabolism

1) Restrictive Dieting

Very low-calorie diets, frequently skipping meals, or yo-yo dieting can actually slow down one's metabolism over time.

When your body isn’t getting enough fuel frequently, it goes into survival mode and starts conserving energy — meaning it burns fewer calories (8).

One study followed The Biggest Loser contestants six years after the show finished and found that most had regained a signifcant amount of weight lost, and their metabolisms were burning 700 fewer calories per day on average (5).

Restrictive eating can also affect the thyroid gland, lowering levels of the hormone T3, which plays a big role in important metabolic processes (4). So while crash diets might lead to short-term weight loss, they can backfire in the long run.

2) Chronic Stress

Prolonged high cortisol levels can contribute to insulin resistance, increased abdominal fat storage, and sluggish metabolism.

Chronic stress can wreak havoc on our hormonal system and impact metabolism. Stress affects ovulation for women, fertility in both sexes, down-regulates thyroid function (3, 9), and interferes with blood sugar balance. Stress disrupts hunger and fullness cues, leading to under-eating, overeating and increased cravings (8).

3) A Sedentary Lifestyle

Muscle is highly metabolically active tissue, particularly during exercise, and requires large amounts of oxygen and nutrients to function optimally.

Lacking regular movement can slow your metabolic fire. Periods of inactivity can reduce muscle mass, decrease insulin sensitivity, and slow down calorie burning, even if you’re eating well (2).

Things to Help Metabolism

4) Eating Enough (and Regularly)

When you consistently eat too little, your body thinks it's in survival mode and slows down metabolism to conserve energy.

Fuelling metabolism is like stoking a fire — sufficient calories and nutrients are essential for that strong metabolic burn (8).

Ensure you are eating above your Basal Metabolic Rate (BMR) - your body's base caloric needs at rest - plus your activity levels, to meet your body’s energy needs. Working with a Nutritionist like myself can help you with this, especially if you are wanting to change body composition. Eat every 3-4 hours with balanced meals and snacks to support metabolism, and avoid skipping meals regularly and under-eating.

5) Prioritise Balanced nutrition

Extreme diets that cut out or restrict important food groups can be stressful on the body.

Eating a well-balanced diet that includes enough protein, healthy fats, and complex carbohydrates is key.

Protein helps preserve muscle mass and requires more energy to digest — about 20–30% of protein calories are burned during digestion. Complex carbohydrates support thyroid health and may help regulate active T3 thyroid hormone levels (1).

6) Strength Training

Muscle burns more energy at rest than fat, which helps increase your metabolic rate.

After the age of 30, we naturally start to lose muscle — up to 3–5% per decade (6). Strength and resistance training with resistance bands, weights, or bodyweight exercises helps build muscle and rev up metabolism.

7) Support your Sleep

Poor sleep affects key hunger hormones (ghrelin and leptin), increases cravings, raises cortisol, and disrupts metabolic balance.

Aim for 7–9 hours of quality sleep each night. Try limiting screen time before bed, keeping a consistent sleep schedule, and using calming bedtime rituals to unwind.

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Your metabolism is a reflection of how your body responds to stress, nourishment, sleep, movement, and overall lifestyle. While quick fixes and restrictive approaches may seem tempting, they often do more harm to metabolic health than good in the long run. By understanding what helps and hinders your metabolism, you can take empowered steps toward lasting energy, balanced hormones, sustainable weight management and a healthier relationship with food.

Need Support? If you're feeling stuck, fatigued, or unsure where to start, I’m here to help. I support clients everyday with their metabolism to improve overall health and well-being. Don't miss out on my Winter Wellness Offer and book in for a complimentary

Health Strategy Call.

Yours in Health,

Kristy x

References

1. Brdar, D., Gunjača, I., Pleić, N., Torlak, V., Knežević, P., Punda, A., Polašek, O., Hayward, C., & Zemunik, T. (2021). The effect of food groups and nutrients on thyroid hormone levels in healthy individuals. Nutrition (Burbank, Los Angeles County, Calif.), 91-92, 111394. https://doi.org/10.1016/j.nut.2021.111394

2. Briden, L. (2021). Hormone Repair Manual: Every womans's guide to hormones after 40. Pan MacMillon Australia.

3. Chaudhuri, A., & Koner, S. (202) A Study of Correlation of Perceived Stress and Thyroid Function Among Females in a Rural Population of Reproductive Age Group. Medical Journal of Dr. D.Y. Patil Vidyapeeth 13(1):p 30-36, Jan–Feb 2020. | DOI: 10.4103/mjdrdypu.mjdrdypu_219_18

4. Fontana, L., Klein, S., Holloszy, J.O., & Premachandra, B.N. (2006). Effect of long-term calorie restriction with adequate protein and micronutrients on thyroid hormones. J Clin Endocrinol Metab, 91, pp. 3232-3235. 10.7759/cureus.55567

5. Fothergill, E., Guo, J., Howard, L., Kerns, J. C., Knuth, N. D., Brychta, R., Chen, K. Y., Skarulis, M. C., Walter, M., Walter, P. J., & Hall, K. D. (2016). Persistent metabolic adaptation 6 years after "The Biggest Loser" competition. Obesity (Silver Spring, Md.), 24(8), 1612–1619. https://doi.org/10.1002/oby.21538

6. Harvard Medical School (2016). Preserve your muscle mass. www.health.harvard.edu/staying-healthy/preserve-your-muscle-mass

7. Pontzer, H. et al. (2021). Daily energy expenditure through the human life course. Science 373,808-812. DOI:10.1126/science.abe5017

8. Tribole, E., & Resch, E. (2020). Intuitive eating: a revolutionary anti-diet approach. 4th edition. St. Martin's Essentials.

   http://www.health.harvard.edu/staying-healthy/preserve-your-muscle-mass

9. Walter, K. N., Corwin, E. J., Ulbrecht, J., Demers, L. M., Bennett, J. M., Whetzel, C. A., & Klein, L. C. (2012). Elevated thyroid stimulating hormone is associated with elevated cortisol in healthy young men and women. Thyroid research, 5(1), 13. https://doi.org/10.1186/1756-6614-5-13