If you have more than a passing interest in nutrition and weight management, you probably pay attention to the number of calories in your food. Calories are the unit of measure used to describe how much energy is in the food you eat.
What are calories?
A calorie, which is a unit of heat, is the amount of energy needed to raise the temperature of 1 gram of water through 1 °C (equal to 4.1868 joules in metric units).
It is generally accepted that if you want to lose weight, you need to consume fewer calories to force your body to make up this energy deficit by burning body fat – body fat being stored energy.
But does that mean you need to weigh and measure your food, calculating the number of calories you are eating, and track your daily activities to see how many calories you have burned? Not necessarily…
Calorie counting advantages
Before we discuss some of the disadvantages associated with calories, let’s briefly look at the advantages of being more calorically aware. After all, counting calories has been proven to be an effective way to lose weight for some people…
Increases nutritional awareness – for someone who never really thinks about food, counting calories can teach food awareness which is the first step in making better food choices. Many calorie-counting neophytes are often surprised to discover just how many calories are in their favorite foods and drinks.
Provides nutritional targets – counting calories provides a means to restricting food intake that is tangible and trackable. Rather than simply “eating less”, a dieter can restrict food intake to a specific number of calories per day. This figure can then be adjusted to suit the individual’s needs.
Helps to quantify exercise – most people are aware that exercise is beneficial for weight loss but knowing approximately how many calories are used during a workout can be a useful motivator. Many people are surprised, however, how few calories an hour of exercise really uses. This helps to reinforce the idea that you “cannot outrun a bad diet” and that eating less is often easier than trying to exercise more.
Calorie counting disadvantages
While counting calories works for some, it is not without disadvantages…
Not all calories are created equal – It is generally accepted that protein contains four calories per gram, carbohydrates contain four calories per gram, alcohol contains seven calories per gram and fat contains nine calories per gram. This premise suggests that all calories are equal irrespective of their source. This, however, is not true, and fails to take into account how calories from different sources are treated in your body.
Different foods require differing amounts of energy to digest, transport, utilize and eliminate. This is commonly referred to as the thermic effect of food, TEF for short. TEF means that, of the food you eat, some of the calories contained in that food are used in the process of digestion etc.
The thermic effect of protein is around 20-35%, the TEF for carbs is 5 to 15% while the TEF for fat is 0 to 5%. This means that 200 calories of protein behave very differently to 200 calories of fat.
The thermic effect of food is seldom, if ever, considered when counting calories but can have a huge impact on how much energy you end up consuming.
Food labeling inaccuracies – food labels are often inaccurate. In fact, according to the FDA, manufacturers are allowed an up to 30% margin of error when labeling food! Food calorie values can also be inconsistent; how do you know how much fat is in a steak for example? It might be a lot more or less than the average on which the database you are using is based. You’ll also find that one database can vary significantly to another. Not knowing how many calories are really in your food means that counting calories can never be an accurate science.
Calorie requirements: an educated guess at best – How many calories do you need to consume per day? There are several accepted ways to establish this figure but all are approximations. Your age, the amount of activity you do, your gender, your muscle versus your fat mass percentage, and your temperature all affect the number of calories you need per day and varies constantly.
Basing your food intake on your estimated energy expenditure means that you are just as likely to be consuming too many calories as you are too few and it’s highly unlikely that many dieters adjust their food intake to reflect their energy expenditure. Picking a set number of calories per day irrespective of activity levels makes very little sense.
Exercise equipment inaccuracies – many exercisers use the calorie counters of exercise machines to measure the effectiveness of their workouts. Unfortunately, these counters are inaccurate. The calculations used to estimate calorie expenditure vary from one manufacturer to the next and are also likely to differ from machine to machine.
Some exercisers will even choose exercises based on how many calories a machine tells them they have burnt despite the fact it is exercise intensity and not exercise modality that affects energy expenditure the most.
Counting calories can be time-consuming – if you do choose to count calories, you will need to invest plenty of time and effort into weighing, measuring and recording the food you eat. This is easier than it used to be as there are apps and online nutrition databases that mean much of the work is done for you but it’s still a time-consuming process – especially if you eat a lot of fresh food that doesn’t come pre-packed and labeled. For some, this process is more effort than it’s worth and is soon forgotten.
Takes the emphasis off food quality – focusing on calories means that it’s very easy to forget all about good nutrition. For example, if you have 300 calories left of your daily food allowance, it’d be very easy to eat a candy bar instead of something more nutritious like some fruit. People who count calories often become very adept at making food substitutions – one less apple for one more cookie for example. There is more to weight management and healthy eating than the number of calories in your food – vitamins, minerals and fiber are all just as important as calories.
Should YOU count calories?
Basing all your nutritional decisions on counting calories is a mistake – there are just too many variables in play to make this an accurate way to control food intake. However, as an occasional exercise to get a ball-park figure of how much energy is in the food you eat, it can be useful. Anything that makes you more “food aware” is a good idea but, when it comes to eating for health and weight management, what you eat is just as, if not more, important than how much.
Count calories occasionally as an educational exercise but there is no need to weigh and measure everything you eat. Instead, focus on eating healthily and sensibly.