Types of Variables That Contribute to Energy Expenditure
Understanding how to efficiently monitor variables that contribute to overall caloric expenditure is an imperative skill when aiming to lose body fat. This blog will cover two variables that are invaluable tools to utilise when the goal is fat loss/increasing energy expenditure.
N.E.A.T activity stands for “Non-Exercise Activity Thermogenesis”, this is essentially the activity in which you carry out your daily activities, from doing the dishes, to taking the bins out. All such menial tasks that are deemed insignificant are actually burning a more significant number of calories than you think. So long as you are not specifically going out of your way to exercise (e.g. play sports or attend the gym), any activity that demands some physical contribution can be classed as N.EA.T.
Typically for those who are beginning the fat loss process, increasing N.E.A.T in accordance with lifestyle, such as walking to and from work and playing outside with the kids more frequently is an excellent start point. These kinds of activities have the capacity shift one’s energy balance into a slight deficit (provided other variables such as diet and training are optimised), this is an idealistic approach to fat loss/ energy expenditure as opposed to a drastic reduction in caloric intake or exceptionally long, repetitive bouts of cardio.
Another imperative tool one can utilise before the reduction in calories or addition of cardio is to utilise a step counter, these can be found on your phone, however, fitness trackers such as the Fitbit (see blog on fitness trackers) are significantly more precise and although the energy expenditure figures they provide may not be accurate, they are still an excellent pedometer amongst other things.
Many people working a desk job or other sedentary occupations will be surprised to find out just how little steps they may be achieving daily, having a fitness tracker raises awareness of a lack of activity and may encourage less sedentary behavior. As mentioned above, taking the option of walking to and from work is an excellent start to increasing daily expenditure/ step counts. It has been recommended that a step count of approximately 10,000 per day is sufficient for the average person, most people will find that this is not being achieved on the average day, achieving this target should be made priority and should be increased/ decreased in accordance with recovery/ progress
TEF, otherwise known as the “Thermic Effect of Food”, is the energy required for digestion, absorption and disposal of ingested nutrients. Many do not understand that calories are essential in order for our bodies to digest and assimilate nutrients, the rate at which calories are burned through TEF is subjective to the food source ingested.
TEF typically equates to around 10% of an individual’s caloric expenditure and can only be accurately measured through lab-based assessment, with 20% of expenditure coming from N.E.A.T, 10% from intentional exercise and the remaining 60% from basal metabolic rate (BMR).
There are varying physiological factors that contribute to the rate of TEF, these include:
- Age: TEF decreases with age even after adjusting for other contributing factors.2
- Insulin resistance: The presence of type 2 diabetes and obesity seem to reduce TEF, perhaps making weight loss more difficult as a result.
- Physical activity level: In both younger and older adults, physical activity increases TEF. TEF is 31% to 45% higher in physically active individuals of various age groups compared to their sedentary counterparts
When considering the individual macronutrient input towards the rate of TEF, compared to high-carbohydrate or high-fat meals, high-protein meals have been associated with a 17% increase in TEF. Certain types of dietary fat, including medium-chain triglycerides, also appear to raise TEF temporarily. Unprocessed foods that are higher in dietary fiber also require more energy to break down, boosting TEF compared to highly processed foods
This is the rationale behind an increase in protein-based foods when the goal is fat loss, as not only are they imperative for recovery and performance, they are also beneficial in raising the rate of TEF, thus contributing to a higher caloric output.
There is some common misconception to the presence of “negative calorie” foods, which is primarily based around t he principle that certain foods such as fibrous fruit and vegetables contain less calories than they burn, this is false and there is no scientific evidence that suggests the existence of such food.
By Tireoghain O’Neill