Let’s Talk Metabolism

Metabolism is the process by which your body converts what you eat and drink into energy.

During this complex biochemical process, calories from food and beverages are combined with oxygen to release the energy your body needs to function.

Any excess that is not required by the body is stored, either as fat or glucose in cells. When your body cannot source energy from food, it turns to energy stored in cells; first, the glucose, and then the fat, to use as energy sources.

You’ve probably heard of metabolic rate and how it affects your weight, but what is it?

Basically, your metabolic rate is a way of expressing just how many calories your body uses per day in order to run your body. This number is also called your Total Daily Energy Expenditure, a term I prefer because it states the obvious in the name.

Total Daily Energy Expenditure, or TDEE, is a phrase that you might come across frequently. It represents the absolute total number of calories that your body uses per day. It takes into account every single calorie you burn, from eating, breathing and generally existing, to calories burnt from general movement and activity, as well as exercise.

There are numerous factors that play into your metabolism and that affect your total daily energy expenditure (TDEE). Some of these, such as genetic factors, we can’t change. But there are numerous factors that we can get to work for us.

In order to maximise fat burning and weight loss (and later to optimise our bodies to remain at our target weight), understanding and manipulating our metabolic rate is vital!

One of your main goals whilst following The Four Week Fat Blast is to maximise your metabolic rate as much as possible, in order to burn as many calories, and as much body fat, as possible!

Here are some of the factors that affect our metabolism.

Genetics: Unfortunately, nothing can be done about this; however, it is easy to overstate the importance of genetics upon weight and metabolism, or even to use it as an excuse.

If your family all carry a few extra pounds, it may well be that you have been taught a few bad habits by family members that make weight loss harder and restrict your metabolism, rather than you all having a low metabolic rate purely through genetics.

Muscle Mass and Body Composition: Muscles work for your body, and need a constant energy supply to be maintained. This means that muscle mass plays a huge role in your metabolic rate.

One of the easiest, most consistent and long lasting ways of increasing your metabolic rate is to start muscle building exercises and to build more muscle mass.

More muscle means more calories burned through- out the day, which can only mean good things for your weight! Fat, on the other hand, is not very metabolically active, as it just sits there, being fat.

Thermogenesis: Thermogenesis is the process of heat creation in the body, a process that naturally burns a significant amount of calories. There are several different ways to increase thermogenesis in the body, thereby burning more calories.

Thermogenic Food: There are numerous different foods, drinks and supplements that can stimulate thermogenesis; we discuss these in much greater detail in the supplements section, but green tea and chillies are both good places to start.

Cold-Induced Thermogenesis: Humans are warm-blooded, meaning that our bodies regulate our temperature to 37 degrees Celsius. By making our bodies work harder to stay at this temperature, we can burn more calories.

The most famous example of cold-induced thermogenesis comes from Michael Phelps, who claimed to eat over 9000 calories per day at the height of his Olympic training.

His expected metabolic rate (based upon weight and muscle mass) and calories burnt in daily exercise would not be enough to counteract this huge intake alone; but as he trains in a cool pool, he burns more calories through cold- induced thermogenesis.

Water: Drinking cold water stimulates thermogenesis too. In fact, studies suggest that drinking 500 ml of 22 degree water caused an additional burn of 24 calories over the next hour.

Two litres of water per day could burn as much as 100 additional calories.

So be sure to drink cold water to burn even more calories, since it needs to be heated to 37 degrees before it can be used by the body.

Thermic Value of Digestion: The process of digesting food burns calories, but not all food has the same thermic value. Protein has the highest thermic value; for every 100 calories of pure protein eaten, the body burns 30 calories to digest it.

Fat, on the other hand, has a very low thermic value of 3%, meaning that the body would only expend three calories in the process of digesting 100 calories of fat.

Carbohydrates fall somewhere in the middle but are more variable; they typically have a thermic value of 5-10%, with simple sugars being easier to digest, but more complex carbohydrates requiring slightly more effort.

Overall, the thermic effect of food may account for up to 10% of total calories expended daily.

Movement, activity and exercise: All movement burns calories, and the more you move, the more calories you burn! Exercise not only burns calories while you do it, but it boosts your metabolism for a short time afterwards too.

In conclusion, it’s evident your metabolism can be affected by many different factors.