Tuesday Tip: Can you boost your metabolism? 🤔
You may have read about various ways to boost your metabolism and burn more calories. But is this really possible?
‘Metabolism’ consists of 3 components:
⁃ 60-70 % basal/resting metabolic rate (bmr) – energy burnt at rest
⁃ 10 % Thermic effect of food (TEF) – energy burnt digesting/storing food.
⁃ 20-30% Activity Energy Expenditure (AEE) – 10-15 % is energy burnt through physical activity (intentional exercise) and the remainder is Non-Exercise Activity Thermogenesis (NEAT) -all activity that isn’t intentional exercise. NEAT is the most variable component of your metabolism and can account for 15% of total energy expenditure in sedentary individuals and up to 50% in active individuals.
Can you boost these? Short answer not by much sadly!
Your BMR is determined by age, sex, height, muscle mass, genetics which you can’t change much (I’ll come back to the muscle mass).
Eating more protein can increase your metabolic rate as it has the highest Themis effect (takes more cals to digest) BUT TEF only accounts for 10% of total energy expenditure. So this isn’t going to have a significant effect.
Increasing physical activity will increase your metabolic rate BUT, unless you train for several hours per day, the magnitude of this
increase isn’t as much as you think. What about increasing muscle mass? Well yes more muscle increases your BMR so you burn more at rest BUT again the overall impact isn’t as great as you’re led to believe. 1kg muscle burns around 13 cals per day so if you added 5kg muscle (which is a lot!) you’d be burning an extra 65 cals a day.
What about metabolism boosters/fat burners etc? The main ingredient in these “metabolism boosters” is caffeine. And while it’s true that caffeine has a “thermogenic effect” 100mg of caffeine only increases energy expenditure by 3-4% and it diminishes as you build a tolerance.
The one component that can significantly impact metabolic rate is NEAT (e.g. walking, standing, fidgeting, house work, gardening etc ). In studies most of the variability in energy expenditure between individuals is due to differing levels of NEAT which can vary by over 1000 calories per day.
So really the most significant impact on metabolism is to avoid being sedentary and to move more throughout the day like interspersing sitting with standing, taking
breaks to walk and move, using the stairs, etc. So avoid those expensive supplements and fad diets/exercise trends and stick to the basics!
Happy Tuesday 🤗