top of page

What Slows Metabolism?

Updated: Sep 11

by Harmony Fitness/Ece, 9/ 2023

Metabolism is a chemical process that converts food and drink into energy for survival. It works even while we sleep for;

  • Breathing

  • Circulating blood.

  • Digesting food.

  • Growing and repairing cells.

  • Managing hormone levels.

  • Regulation of body temperature.

Basal Metabolic Rate (BMR) refers to the energy your body needs to keep your organs running while you're resting. Gender, age, height and weight will affect the results.

People with a fast metabolism can easily lose weight by consuming more food and even burn calories while resting, but people with a slow metabolism need less food and more time to lose weight.

What are the factors that slow down the metabolism?

  1. No physical activity/ sedentary lifestyle/ lack of strength training

  2. Diet

3. Hormones

4. Sleep

5. Stress

How to improve metabolism?

  1. Exercise (being physically active)

  • HIIT (High-intensity interval training ) / AMRAP (As many repetitions as possible)

2. Diet

3. Sleep

What are the factors that slow down the metabolism?

1. No Physical Activity/ Sedentary Lifestyle/ Lack of Strength Training

Iron that doesn't work rusts. Sedentarism can cause heart problems, diabetes, cholesterol, cancer, etc. will increase the risk of diseases. Every hour (with >10 hours and <5 hours of sitting times a day) is cut off from our life. Bu günlerde evden çalışmanın bir yandan avanjalı olması bir yandan da daha çok oturmaya teşvik etmesi bu durumu zorlaştırmakta. Tüm gün oturarak çalışanlar, her 1 saatte bir 1 veya 5 dakika ayağa kalkmaya çalışın.

I want to remind you that activities in daily life activities burn calories too, such as cleaning, running after the child, watering the flowers, parking your car far away to walk a bit, etc. The more you move and the more active you are, the faster your metabolism will be. But that doesn't mean you have to spend 7 days a week exercising :). In other words, being active for 1 hour moderate/vigorous 4 times a week will help you maintain your fit body.

METs (metabolic equivalent of task) is the amount of energy used while sitting quietly. For example, walking at a moderate pace of 2.8-3.2 miles per hour (mph) on a level, firm surface is approximately 3.5 METs, which means that the body is using 3.5 times the amount of oxygen than is required when sitting still at rest. Here are the suggestions for how many hours will it be active according to the person;

  • Children ages 3 through 5: At least 3 hours daily.

  • Children and adolescents ages 6 through 17: At least 1 hour daily of moderate-to-vigorous activity with both aerobic and strength movements.

  • Adults: At least 150 to 300 minutes weekly of moderate-intensity aerobic exercise and at least 2 days weekly of muscle-strengthening exercises

  • Older adults: Same as adults plus include balance training.

  • Women who are pregnant or postpartum: Aim for 150 minutes weekly of moderate-intensity aerobic exercise.

  • Adults with physical disabilities and chronic conditions: Similar to adults but must be personalized.

On the other hand, strength training will increase your muscle mass, so it will also allow you to burn more calories easily and this will affect the resting metabolic rate. 'Muscle mass decreases by about 3-8% per decade after the age of 30, and this decrease rate increases even more after the age of 60'.

can exercise improve metabolism

One study found that overweight young adults with a previous sedentary life who did 11 minutes of strength training for 6 months, 3 times a week had a significant increase in energy expenditure. For this reason, while strength training accelerates your metabolism, it will prevent muscle loss and obesity, and the effort you spend in your daily life activities will become easier as you get stronger. (carrying a shopping bag, carrying your baby, moving things, carrying a laundry basket, etc.). You can check out my programs like express or full body workout to do 10 minutes a day.

2. Diet

  • Cutting Calories Suddenly and in Excess /Night Time Eating/ Skipping Meals

Suddenly cutting calories more than usual or fasting won't get you anywhere, it'll make your leptin unable to control your appetite. Leptin is a protein hormone produced in adipose tissue; It plays a role in the regulation of appetite and metabolism. When you gain weight, leptin will be produced to reduce fat storage. However, since these fats will cause leptin to work less, you will have a hard time losing weight. Ghrelin is the "go" hormone that tells you when to eat, so leptin is the hormone that tells you to stop.

Therefore, if your body doesn't have enough energy (carbs and healthy fats from food) to use it, it uses muscles to produce it. As I said before, muscle loss will lead to a slowdown in metabolism.

What to do instead;

Eat moderate amounts of Good Fats

Monounsaturated fat – good sources include:

  • Olive, canola, peanut, and sesame oils

  • Avocados

  • Olives

  • Nuts (almonds, peanuts, macadamia, hazelnuts, pecans, cashews)

  • Peanut butter

Polyunsaturated fat – good sources include:

  • Sunflower, sesame, and pumpkin seeds

  • Flaxseed

  • Walnuts

  • Fatty fish (salmon, tuna, mackerel, herring, trout, sardines) and fish oil

  • Soybean and safflower oil

  • Soymilk

  • Tofu

Bad / Trans fat – primary sources include:

  • Commercially-baked pastries, cookies, doughnuts, muffins, cakes, pizza dough

  • Packaged snack foods (crackers, microwave popcorn, chips)

  • Stick margarine, vegetable shortening

  • Fried foods (French fries, fried chicken, chicken nuggets, breaded fish)

  • Anything containing hydrogenated or partially hydrogenated vegetable oil, even if it claims to be “trans-fat-free”

Saturated fat. While not as harmful as trans fat, saturated fat can raise bad LDL cholesterol, and too much can negatively impact heart health, so it's best consumed in moderation. Saturated fat – primary sources include:

  • Red meat (beef, lamb, pork)

  • Chicken skin

  • Whole-fat dairy products (milk, cream, cheese)

  • Butter

  • Ice cream

  • Lard

  • Tropical oils such as coconut and palm oil

that will make you less hungry and help you lose fat, fresh fruits and vegetables, lean protein and healthy carbohydrates. Proteins are good sources to keep you full.

'Eating in late time also affected the hunger and appetite-regulating hormones, leptin and ghrelin. Leptin dropped by 16% when folks ate four hours later, the study showed. Cutting too many calories suddenly causes you to starve, which in turn causes you to snack late at night. Therefore, whatever is eaten at night turns into fat due to the slowing of metabolism.

eating late night and weight gain

Accordingly, eating late at night will affect your daily routine such as sleeping, skipping breakfast, avoiding healthy eating and focusing on more fast food, not having time to do sports, etc. and will cause you to gain weight. Where is order, where is success!

How about trying to eat earlier for 3 months?

Think of your diet like a pyramid and start with a big breakfast within 1 hour of waking up and smaller at night. It is recommended to give your body 12 hours at night to rest and repair. Also, eating something small every 3-4 hours can keep your metabolism raised. For example, I don't eat after 6 p.m. at the maximum, I have been able to stick to this routine for years. Try it for 3 months, then write me a comment ;)

  • Too Much Sugar

Eating too much sugar and refined carbohydrates raises your insulin levels and glucose is stored as visceral fat in the abdomen. Therefore, having too much glucose in your body causes inflammation and the body has trouble performing functions such as insulin balance, energy supply, or sleep. This causes your metabolism to slow down.

Sugar is addictive and there is a lot of sugar in ready food and especially in drinks. 1 glass of orange juice is equal to 5-6 oranges and contains 24g (6 spoons) of sugar. Moreover, these fruit juices do not keep you full, but if you try to eat 6 oranges at a time, it won't be possible. If you are thirsty, drink water and avoid sugary drinks.

WHO (World Health Organization) recommends that the total sugar intake should be 10% of the total daily energy intake, and that added sugar should be less than 5%. Added sugars are monosaccharides, disaccharides, and syrups that are added to foods when they are processed or prepared.

Eating enough fruit a day will eliminate your sugar cravings. Although I would advise you to stay away from added sugar, don't limit yourself too much. Because the more you stay away from something you love, the more you will crave it. Therefore, try to reduce sugar hunger by choosing black chocolate or a similar low-calorie, fat-free dessert. For example, instead of eating donuts (74 gr=454 calories), you can prepare pudding (1 cup/240gr= 300 calories) at home; by adding banana, milk and very little flour, cocoa and coconut on it, so you can prevent the sweet crisis with a very light and satisfying dessert.

Would you like to live without sugar for 21 days and see the difference?

daily sugar intake

Daily sugar intake recommendations for adults. WHO, World Health Organization.

harmony fitness

(A) Amount of sugar intake through processed foods by age group. (B) Distribution of main sources of sugar in beverages.

3. Hormones

Hormonal imbalance causes weight gain. These hormones, which allow our bodies to function normally, can be disrupted by living habits, environmental factors, or medical conditions. There are more than 50 hormones in our body such as insulin, cortisol, melatonin, estrogen, thyroid, and so on.

If you have been dieting and doing sports for a long time but can't get results, plus if you can't sleep or if you feel tired despite getting enough sleep you'd better get your hormone levels checked. Moreover, if you are in a state of constant stress, try to stay away from stress and clear your mind by doing some mindfulness or hypnosis.

In other words, they are all interconnected, good sleep, regular exercise, healthy eating, keeping weight in balance, and staying away from stress will help you reach a healthy body and keep your hormones working properly.

4. Sleep

Sleep is the most important factor for the proper functioning of the body, brain and muscle repair after exercise, therefore it has a strong connection with metabolism. The fat-burning process takes place during DEEP SLEEP, so you should sleep at least 7-9 hours a day. Indeed, sleeping for short hours, and waking up late at night no matter what time you fall asleep (stress or other factors), makes you tired all day long and can lead to obesity and diabetes.

sleep cycle through the night

Circadian rhythms are an internal cycle clock that works depending on the sun's rays and fulfills the physical and mental functions of the body. Applying our daily life accordingly without disturbing this order will ensure that our metabolism works regularly, you can examine this in the picture below.

circadian rhythm

In addition, the use of social media or exposure to technological devices before bedtime will disrupt the sleep pattern. In a tired body, it can lead to attention deficit and making wrong decisions. As I explained above, when sleep deprived, snacks will increase late at night and foods containing more calories will be preferred with wrong decisions.

Ways to improve your sleep & reduce weight;

  • Create a routine (Go to sleep and wake up at the same times and stick to the schedule even on your days off)

  • Stay away from technology 1 hour before your bedtime

  • Use your bed only for sleeping

  • Exercise regularly

  • Eat light meals for dinner

  • Avoid caffeine (coffee, tea, chocolate) after 2 pm

  • Drink Turkish Ayran at dinner

Turkish Ayran Ingredients

Yogurt, Water, Salt, Dried Mint (optional)

Add yogurt to a glass of water or mixer bowl, then add water and salt and mix for a few seconds. You can sprinkle some mint on it and serve. 2 spoons of yogurt may be enough for a glass, you can increase the yogurt for a denser consistency. Ayran will make you sleepy.

“Early to bed, early to rise, makes a man healthy, wealthy and wise.”

Benjamin Franklin

5. Stress

Stress takes an inevitable place in our lives, stress at home or work causes negative damage to the body, slowing down the metabolism and causing us to gain weight.

Cortisol is the fight-or-flight hormone, equipping the individual to meet the demands of daily life and to handle stressful situations. When extra cortisol is present and if the body cannot use it properly, which leads to obesity and diabetes mellitus.

When it comes to flying or fighting, I recommend flying (in your MIND!) in stress-related topics. You can't fight stress, you either get stressed and lose your health, or ignore what's bothering you and have peace. You can join my 21-day meditation online program to clear your mind a little by leaving 5 or 10 minutes to yourself.

How to improve metabolism?

1. Exercise (being physically active)

  • HIIT (High-intensity interval training ) / AMRAP (As many repetitions as possible)

The overall energy expenditure of fat and carbohydrate depends on exercise intensity, duration, training status, and diet. However, it has been determined that maximum fat oxidation rates occur when moderate-intensity exercise is performed.

HIIT is a workout done by doing some high-intensity exercises (>90% VO2 max) one by one for 30-40 seconds, resting for 10 seconds between each, and then resting for 60 seconds after completion. Amrap, for example, is to repeat 4 exercises as fast as possible without resting within a certain period, such as 8-20 minutes.

Sample of Amrap & HIIT


- 10 Lunge

- 10 Shoulder Press

- 10 Squat & Kick Back

- 20 Reverse Crunch

HIIT (20sec x 15sec)

- High Knee

- Burpees

- Skater

- Side Planks with Rotation

- Standing Punches

- Flutter Kicks

Both aim to lose fat, increase endurance, build strength and gain some muscle. It is a solution to the excuse of time offered to exercise consistently, taking 10-15 minutes 3 times a week can prevent weight gain or help you reduce your weight. If you don't like doing cardio or running long hours, you can consider them as an alternative option. If you choose training that suits your lifestyle and that you can continue for a long time, you can get good results and you will not look for an excuse to stop.

On the other hand, such high-intensity exercise will improve the cardiorespiratory system (protection from factors associated with causing cardiovascular disease), your mental health, self-confidence, distraction, and produce endorphins (hormones that reduce stress and improve mood/reduce depression).

As I explained in point 1 above, being active and doing a little something a day will improve your life. When you increase your muscle mass, your metabolism will automatically accelerate. Don't waste your day doing nothing.

2. Diet

Eating healthy will protect your body from diseases and prevent obesity. Therefore, including all macronutrients in a balanced way (55%-65% carbohydrates, 7%-20% protein and 15-30% fat) will take your life one step further.

food balance wheels

Food balance wheels. Adapted from the Ministry of Health and Welfare and the Korean Nutrition Society.

  • Water

Drinking a glass of water an hour can speed up your metabolism by up to 25% (8 hours = 2 liters). As much hydrated body as possible will work well, help you get some energy during exercise and rebound after exercise, plus you'll have great skin. Our muscles are built with water, so drinking too much water a day will facilitate growth.

On the other hand, it suppresses hunger, so it can help you avoid snacking between meals. To encourage drinking water, you can add some flavors like fruits or lemon, cucumber, etc.

The benefits of apple cider vinegar (1-2 drops), lemon, and turmeric are countless, they help digestion, ailments, and inflammation, and have a relaxing effect on the chest and throat. Drinking these on an empty stomach in the morning speeds up the metabolism. I tried this for a month and I had more energy during the day. Even though I didn't like the taste, I continued with it because it felt like it had done something good to my body. Give it a try ;)

  • Protein in Every Meal

Including protein in your diet is essential for building muscle, preventing muscle loss and strengthening bone structure. The Recommended Dietary Allowance (RDA) states that you need 0.8 grams of protein for every kilogram of body weight. The joint American College of Sports Medicine and Academy of Nutrition and Dietetics position statement calls for 1.2 to 1.7 g/kg for strength athletes and 1.2 to 1.4 g/kg for endurance athletes.

I can't pass without mentioning this, although protein is important, too much protein is harmful. Therefore, it will cause bloating, that is, this excess protein will turn into fat, not energy. It is beneficial to get a balanced intake of all macronutrients at every meal. On the other hand 'excessive protein consumption, whether from food sources or by liquid or powder supplements, may cause dehydration, as well as negatively impact the kidneys and bones'.

Divide your total protein amount by 3 and add it to each meal, for example, if you have 80g of protein for a day, you can divide it into 20-30-30g.

How do we get 30g of protein:

135g chicken 150g beef 180g white fish

170g prawns 5 whole eggs 375g natural yoghurt

130g tuna (drained weight) 250g cottage cheese 600ml milk

35g whey 160g black bean (dry) 400g rice

100g soy 100g lentil (dry) 230g oat or quinoa (dry)

1450g potato

  • Coffee/ Green Tea

A standard cup of green tea (250 mL) contains between 100 and 300 mg of total catechins and 50 and 90 mg of caffeine. Catechin speeds up metabolism. In a study conducted with 109 people in China, it was determined that green tea catechins caused a reduction in visceral fat after 12 weeks despite no change in their diet or activities.

Coffee and green tea give the body more energy by thermogenesis effect. Some studies suggest that this heat burns more calories even at rest, and coffee helps with weight loss if drunk before training.

Some studies have stated both coffee and green tea prevent diseases such as diabetes, obesity, and Alzheimer's disease and reduce inflammation.

Although research indicates that coffee can help you lose weight, the opposite can happen when you add too much sugar, or it can cause you to gain weight if it interrupts your sleep, which can be attributed to the 'sleep' factor above. On the other hand, we understand the importance of counting calories once again, choosing the ones that we crave with fewer calories (no sugar coffee) will form the basis of a healthy life.

3. Sleep

I have already mentioned the importance of sleep for body function, please click here to jump up, but in short, our body needs 7-9 hours to offer you a better and quality life, do not skip it, otherwise you will pay more seriously.

Finally, I would like to add that this article is a summary of the factors that are important in improving our lives based on the research and review of all the articles on metabolism.

If you have experience or suggestions to speed up your metabolism, please feel free to get in touch, I'd love to hear it.

References 1. Metabolism, Cleveland Clinic

2. Park JH, Moon JH, Kim HJ, Kong MH, Oh YH. Sedentary Lifestyle: Overview of Updated Evidence of Potential Health Risks. Korean J Fam Med. 2020 Nov;41(6):365-373. doi: 10.4082/kjfm.20.0165. Epub 2020 Nov 19. PMID: 33242381; PMCID: PMC7700832.

3. Staying Active, Harvard T.C. Chan,may%20use%208%2D9%20METs.

4. Volpi E, Nazemi R, Fujita S. Muscle tissue changes with aging. Curr Opin Clin Nutr Metab Care. 2004 Jul;7(4):405-10. doi: 10.1097/01.mco.0000134362.76653.b2. PMID: 15192443; PMCID: PMC2804956.

5. Kirk EP, Donnelly JE, Smith BK, Honas J, Lecheminant JD, Bailey BW, Jacobsen DJ, Washburn RA. Minimal resistance training improves daily energy expenditure and fat oxidation. Med Sci Sports Exerc. 2009 May;41(5):1122-9. doi: 10.1249/MSS.0b013e318193c64e. PMID: 19346974; PMCID: PMC2862249.

6. Caitlin Beale, MS, RDN, The Metabolic Advantages of Strength Training, Signos

7. Arem, R. (2014). The Protein Boost Diet: Improve Your Hormone Efficiency for a Fast Metabolism and Weight Loss. Simon and Schuster.

8. Stanhope KL. Sugar consumption, metabolic disease and obesity: The state of the controversy. Crit Rev Clin Lab Sci. 2016;53(1):52-67. doi: 10.3109/10408363.2015.1084990. Epub 2015 Sep 17. PMID: 26376619; PMCID: PMC4822166.

9. Denise Mann, Late-Night Meals Especially Bad for Weight Gain: Study. Usnews

10. Abbas Smiley, Stephen Wolter, Dana Nissan. Mechanisms of Association of Sleep and Metabolic Syndrome. J Med - Clin Res & Rev. 2019; 3(3): 1-9.

11. Hirotsu, C., Tufik, S., & Andersen, M. L. (2015). Interactions between sleep, stress, and metabolism: From physiological to pathological conditions. Sleep Science, 8(3), 143-152.

12. Rabasa, C., & Dickson, S. L. (2016). Impact of stress on metabolism and energy balance. Current Opinion in Behavioral Sciences, 9, 71-77.

13. U Rock Girl, 2015. How Much Protein Do We Actually Need? ACE Fitness,,grams%20of%20protein%20a%20day.

14. Apple Cider Vinegar Vs Lemon Juice For Weight Loss. Trim Habit.

15. Johnson, M., & Pye, H. The First Pillar of Beyond Nutrition's Fundamentals

16. 2022. 6 Reasons To Make AMRAP Workouts Part of Your Exercise Routine. Cleveland Clinic.

17. Kravitz, L. (2014). Metabolic effects of HIIT. IDEA Fitness Journal, 11(5), 16-18.

18. Effects of catechin-enriched green tea beverage on visceral fat loss in adults with a high proportion of visceral fat: A double-blind, placebo-controlled, randomized trial

19. Murray, A., & Farina, L. (2019). The 4-Week Fast Metabolism Diet Plan: 100 Recipes to Reset Your Metabolism and Lose Weight. Callisto Media, Inc.

20. Lim S. Eating a Balanced Diet: A Healthy Life through a Balanced Diet in the Age of Longevity. J Obes Metab Syndr. 2018 Mar 30;27(1):39-45. doi: 10.7570/jomes.2018.27.1.39. PMID: 31089539; PMCID: PMC6489487.

21. Sukel, K., 2021. Understanding Sleep. Dana.

22. Suni, E., & Dr. Vyas N., 2023,. Stages of Sleep: What Happens in a Sleep Cycle.

23. Hodgson AB, Randell RK, Jeukendrup AE. The effect of green tea extract on fat oxidation at rest and during exercise: evidence of efficacy and proposed mechanisms. Adv Nutr. 2013 Mar 1;4(2):129-40. doi: 10.3945/an.112.003269. PMID: 23493529; PMCID: PMC3649093.

24. 2023. Can Coffee Make You Gain Weight? 5 Surprising Health Benefits of Coffee. Health Fitness Analysis.

25. Izadi V, Larijani B, Azadbakht L. Is Coffee and Green Tea Consumption Related to Serum Levels of Adiponectin and Leptin? Int J Prev Med. 2018 Dec 5;9:106. doi: 10.4103/ijpvm.IJPVM_37_14. PMID: 30622689; PMCID: PMC6298130.

26. Forsyth, A., 2021. Does Coffee Boost Your Metabolism?

27. Hodgson AB, Randell RK, Jeukendrup AE. The effect of green tea extract on fat oxidation at rest and during exercise: evidence of efficacy and proposed mechanisms. Adv Nutr. 2013 Mar 1;4(2):129-40. doi: 10.3945/an.112.003269. PMID: 23493529; PMCID: PMC3649093.

6 views0 comments

Recent Posts

See All
bottom of page