Back to Basics, Energy Expenditure vs. Energy Intake
Weight loss is one of the most popular topics discussed when it comes to health and nutrition. Many of us are after that ‘magic pill’ to help shed the pounds fast, unfortunately no such pill exists. For several of us, weight loss is more a physiological challenge as well as a lifestyle change. Arguably, the most difficult step is acknowledging that change is needed.
There are many supplements available on the market that can help increase the number of calories expended, alongside a healthy balanced diet and exercise however; it is unlikely these will yield results without the latter. So let’s go back to the basics and look at exactly how weight loss and weight gain occurs in the first place.
Theoretically, weight loss occurs when the energy you intake, which is generated by food you consume, is less than the energy you expend (calories expended via physical activity see image below).
When energy intake is equal to energy expenditure, this is when weight maintenance is achieved. Indeed, there are many factors that can intercept this process for example genetics and hormonal conditions, yet despite this a healthy diet can actually be beneficial in controlling such conditions.
The typical male needs approximately 2,500Kcal (10,500kJ) a day to maintain weight. For females the intake is slightly lower at 2,000Kcal (8,400kJ) a day. In order to lose weight this figure would need to be around 500 calories less a day.
For example; the typical male would need to consume 2000 calories instead of 2500 calories. This would result in approximately 1lb weight loss per week; this rate of weight loss is considered to be healthy weight loss. The same concept applies for weight gain, an additional 500 calories a day would need to be consumed, resulting in 1lb weight gain per week.
Thermogenic products can help to catalyse the number calories expended. Typically a thermogenic formula will consist of stimulants such as; Green Tea, Caffeine and Raspberry Ketones. The theory is thermogenics increase the body’s heart rate and elevate body temperature thereby increasing the amount of calories expended.
Not everyone fits the typical example above therefore, to tailor to your own needs there are a few calculations you can do. The amount of energy you require varies from person to person and is reliant upon your Basal Metabolic Rate (BMR), Physical Activity Levels (PAL) and other factors such as age, gender and height.
BMR is the amount of energy needed to maintain everyday bodily functions such as; breathing and keeping the heart pumping. You can calculate your BMR using the following:
BMR for Males = 66.47 + (13.7 x weight [kg]) + (5 x size [cm]) − (6.8 x age [years])
BMR for Females = 655.1 + (9.6 x weight [kg]) + (1.8 x size [cm]) − (4.7 x age [years])
Energy expenditure = BMR x Physical Activity Level (PAL)
Sedentary Individual: 1.4
Moderate Intensity = 1.6/1.7
High Intensity = 1.8-1.9
Protein and Weight loss
It takes the body longer to digest proteins compared to carbohydrates therefore, protein increases satiety levels (makes you feel fuller for longer) and can help to promote more balanced blood glucose levels. This is why snacking on high protein snacks can facilitate weight loss. Maintaining steady blood glucose levels is an important aspect for a healthy lifestyle and relevant in maintaining your desired weight. The reason for this is rooted in the importance of steady blood sugar levels.
When your blood sugar levels (glucose) fluctuate, this can cause cravings for simple carbohydrates/sugars such as sweet, sugary foods. This is why consumption of these types of foods can potentially lead to weight gain, affect dental health and lead to numerous other complications (see Body Fuel: How Carbohydrates Affect Appetite?)
Top Tip - Don’t cut out all your fats, replace the ‘bad’ fats with ‘good fats’ such as Olive Oils, Fish Oils, Coconut Oil. Switch your baking methods, instead of frying try baking, steaming or stir frying instead.
In essence, weight management is largely determined by the number of calories you expend or intake, with negative energy balance resulting in weight loss and positive resulting in weight gain. As explained above, taking care of your diet and getting the correct balance is crucial to achieving your desired physique.