Your calorie intake is the amount of energy you get from food and drink. This can often be very difficult to determine precisely for a number of reasons:
- This would require precise measurement and tracking of everything we eat and drink. This is possible, and we will discuss later why this could even be recommended for a lot of people for various periods of time and for various reasons, but it requires a certain amount of skill, and is by no means a straightforward process
- Food labels, as you will again discover in a later module, are not 100% accurate, and these variances can vary wildly depending on where you are shopping, how many people the food comes into contact with (which increases the occurrence of human error) and how many ingredients the food has
- Even if you tracked every morsel of food, and compared this to data which was accurate to the joule for the specific foods you eat (consider here that two seemingly identical potatoes, of the same variety but grown in different soil will have slightly different nutritional contents due to the nutrients available to them in that soil), you wouldn’t be getting the whole story. Your calorie intake is more accurately considered to be your calories ‘absorbed’ rather than just calories consumed. Around 2-10% of calories consumed will be lost in faecal matter because absorption is affected by food choice (for instance, higher fibre intakes reduce absorption) preparation techniques, the microbes living in your gut, your genetics, and a number of other things, some of which will be discussed in a later section of this module
With that said, it is very possible, and even easy (when you know how) to ‘ballpark’ your calorie intake by measuring things or even using good practiced judgement. While it’s impossible to be precise it’s practically possible – even easy – to be consistently, roughly accurate. This wouldn’t pass in a scientific lab, but it’s certainly good enough for most to control their weight.