“It’s not only about your workout time, it’s about your total active time” – me on energy expenditure.
Losing and gaining weight is not a complex matter. The equation is as simple as:
Gain weight = calorie in > calorie out
Lose weight = calories in < calories out
This time, instead of focusing on what we eat, I’d like to zoom into the other part of equation: energy expenditure.
Calorie out, also known as energy expenditure, is the total energy we use to survive and perform our daily activities. It consists of the following:
1. BMR (basal metabolic rate)
This is the energy our body use to survive and highly dependents on lean body mass. It’s not only about muscle but also skeleton and other organs. Despite our organs are only 7% of our total body mass, it takes the most energy. BMR is also influenced by body weight. It increases as body weight increases, for example, someone who is 75kg will have higher BMR than someone who is 50kg.
BMR is estimated to be around 60%-70% of total energy expenditure, although percentage can be lower for a very active person.
2. TEF (thermal effect of food)
This is the energy used to process food we eat and it varies per nutrition. Protein has a TEF between 15-25%, carbohydrates 6%, and fat only 3%. In general, TEF is estimated at 10% of total calorie intake. Thus, this is a relatively smallest proportion of energy expenditure.
3. TEA (thermic affect of activity)
This refers to calorie burns during a formal exercise and varies across individual as one person can exercise few times a week while another does not exercise at all. Types of exercise also influences this.
4. NEAT (non exercise activity thermogenesis).
NEAT refers to calories burn during non-formal exercise and this section is usually underestimated. We tend to forget informal exercise as part of the equation. Imagine an office worker who works 6 hours in front of the computer and a nurse who moves around to help patients. These to people will have quite a different NEAT as one is way more active than another.
From those four categories of energy expenditure, “BMR and TEF simply don’t vary that much and while TEA can contribute significantly to calorie expenditure if large amounts of exercise are done, only trained athletes can usually accomplish this. For non-athletes, and outside of some specific disease states, there is no such thing as a slow metabolism (i.e. RMR), only low levels of NEAT.” (McDonald Lyle, 2018, The Women’s Book)
Now – how can we integrate this to our daily life?
BMR can’t be changed much. It will change as our body weight changes but without a huge changes on body weight, it’s not something we can influence. This been said, after a diet cycle, we might want to recalculate our daily calories needs as our BMR might have changed. It won’t be major if we lose 2-3kg but it will be significantly different if we lose 20-30kg.
TEF depends on what we eat. The only way to increase this is by eating more food and this is obviously not a good solution.
Increasing TEA is something we’ve read everywhere. Exercise helps to maintain weight and we must exercise on a regular basis. However, I believe we should exercise regularly to keep ourself healthy and not only to burn more calories. Run more for our heart health, and not because we want an extra slice of cake. Lift more for bone dense capacity and not because we want a hot ass.
Last and most important part is, to have a more active lifestyle. NEAT is one aspect we can influence quite easily but we tend to forget it. A small change as simple as standing while working instead of sitting mean an extra 1kcal/minute. It means 60kcal/hour! Choose a further parking space at your office and do extra steps. Take stairs instead of lift. Those small changes add up. Remember, 20kcal extra for one change would mean 100kcal extra for five different changes.
Another fun part by alternate NEAT instead of TEA is it is not as ‘tiring’ as a formal exercise. Take me during and after lockdown as an example. On both times, I lift for 90minutes per day and cycle to work or at park for 75-90 minutes per day. That’d be my formal exercise. However, I notice when I work from home, I don’t walk around as much as when I’m at the office because of space restriction. It took me to walk a metre or two to go to the toilet at home while it’ll take me almost 10 meters at the office. Multiply that by 4-5 across 8 hours, that’s something, isn’t it?