The word metabolism gets thrown around a lot, especially when talking about weight loss. I'm sure everyone has heard the saying
"Boost your metabolism and you'll speed up your weight loss"
But does that actually work?
Firstly, what actually is your metabolism?
Your metabolism is basically the energy that you need and use everyday to keep yourself alive and breathing. It is affected by many things such as the amount of physical activity that you do, gender, age, hormone function, muscle mass and fat percentage. In other words your metabolism is your Total Daily Energy Expenditure (TDEE) which consists of 3 main parts.
1. The thermic effect of food - This accounts for roughly 20% of how much energy you burn every day. This is the energy it takes to digest all the food that you eat. Some foods can take more effort to digest so burn more calories. With protein around 30% of the total calories will go towards breaking down the food and digestion, where as for carbs it's approx. 10% and fats even less than that. Fibre takes a bit more to digest as it needs to get broken down. So making sure that you are reaching your daily limits for protein and fibre definitely helps to speed up your metabolism.
2. Exercise - This accounts for only 10% of our daily energy expenditure. Sorry to everyone that thought exercise was the main burner of calories everyday. It's actually the amount of calories that you burn outside of exercises sessions that you want to be increasing. Hello to burning more calories while sitting down reading or watching your favourite TV show.
3. Basal Metabolic Rate - A whopping 70% of your daily energy expenditure is coming from your basal metabolic rate. This is the calories you burn with your body doing everything it can to keep you alive everyday e.g heart beating, brain functioning and lungs taking in oxygen. So even if you literally did nothing all day. Did not move a muscle and stayed on the couch, your body would still be burning through energy to keep it alive. Keeping yourself breathing and heart beating is kind of important so it's no wonder that this is the main component.
So what then are a few things you can do to help speed it up?
1. Exercise by doing both HIIT training and weight training
Lots of evidence has suggested that both weight training and HIIT training are the most effective forms of exercise to boost metabolism. Not only have they have both been shown to burn more calories than steady state cardio (such as going for a walk) and in half the time (so great for people who are time poor) but your calorie burn stays elevated for up to 24 hours post session allowing you to burn sometimes an extra 200 or 300 calories. Not a great deal of calories more but if you did that 5 - 6 times per week and were burning say an extra 1200 - 2000 calories a week then that all adds up over time.
2. Build up muscle
Building up your muscle mass through doing weight training 2 - 3 times per week. Muscle is said to burn 6 calories per pound whereas fat is said to burn only 2. Look not a huge difference but again the same as with doing HIIT training, it all adds up over time.
3. Make sure you are actually eating enough
Conversely to what people think, skipping meals and leaving out food groups will slow down your metabolism. This is called metabolic adaptation. When you under feed your body for an extended period of time, your body adapts and reduces the amount of calories that it can run on (bodies are clever like that). So you will not lose weight but become stagnant and sometimes even put on weight. This goes back to the time when food was scarce and out bodies didn't know when the next meal was coming so it went into starvation mode.
4. Ensure adequate protein intake
As shown above, ensuring you get adequate protein can help you burn up to an extra 500 calories per day. This isn't to say cut everything else out of your diet and only have protein. Carbs and fats are needed to help all the organs and systems in the body function, so eliminating those will provide a less than desired effect. But having adequate protein will definitely go a long way to helping you i the weight loss department.
Take home Message
There is not one specific thing that you can do that will magically boost your metabolism.
Making smaller changes everyday though will greatly help to improve it