Calorie counting to lose weight is perhaps one of the most utilised methods of weight loss. Whilst it may work under certain circumstances, at what cost? What is the truth about calorie counting for weight loss?June 20, 2022 11:33 am June 08, 2022 6:30 pm
What is a Calorie?
Anyone who has ever tried a fad diet, or any weight loss diet, has most likely come across calorie counting as a method to lose weight. Counting calories to lose weight is much more complex than what many fad diets may want you to believe. But what is the truth about calorie counting for weight loss?
Firstly, it may be useful to understand what exactly a calorie is. In fact, a calorie is a unit of measure that we use to calculate energy. An object called a bomb calorimeter measures how much energy is contained within a certain food. Another unit of measure which you may frequently see on food labels is kilojoules. One calorie (1 kcal) is essentially equal to 4.2 kilojoules (4.2 kJ).
A Complex System
Calorie counting is based on a system called the Atwater system which dates to the 1800s, this was a method to estimate the number of calories in a specific amount of food based on the total amount of grams of macronutrients (carbs, protein, and fat) that it contains. However, these numbers do not provide information about how much of each macronutrient our bodies can either digest or absorb. Nor do calories tell us how certain foods affect our blood glucose levels for example.
If we take the example of nuts, we can see that calorie counts are not always a reliable piece of information. In fact, the USDA carried out a study which concluded that the calories our body “absorbs” from nuts are on average 32% less than the calorie count listed on food packaging.
Furthermore, this conclusion was made relating to the “average person”. But what does “average person” mean? It’s challenging to make such a generalisation because as we can imagine, people differ widely from one another, and so many factors, from age to gender to bodyweight can influence our daily energy requirements as well as energy expenditure.
Indeed, the USDA study found that the number of calories absorbed from an ounce of almonds varied hugely between individuals, from as low as 56kcal per ounce to as high as 168kcal per ounce!
This goes to show that the exact same number of almonds can translate to very different calorie counts depending on the individual.
“The USDA carried out a study which concluded that the calories our body “absorbs” from nuts are on average 32% less than the calorie count listed on food packaging.”
One Size Doesn’t Fit All for Calorie Counting
The takeaway from this is that we are all different and unique when it comes to our bodies and biology. The truth behind calorie counting for weight loss is that one size does not fit all. Therefore the same food can impact people in very different ways. Overall, calorie counting should not be the be-all and end-all. It’s much more helpful to understand your own body and your own unique nutritional needs. Focus on healthy, balanced food as opposed to obsessing over every single calorie.
Calories In < Calories Out
The logic behind calorie counting for weight loss is the premise that calories in < calories out equals weight loss. In other words, the premise is that if you consume less calories than your body requires to maintain its weight, you should lose weight. Alternatively, if you obtain a calorie deficit by burning more calories than those consumed, according to the equation you should also be losing weight. But is calorie counting really enough to achieve weight loss?
Whilst it is true that to lose weight, you will require an energy (calorie) deficit, there are many confounding factors which can influence your ability to lose weight. For instance, age, gender, hormones, stress levels, and even the amount/quality of your sleep can all impact weight balance.
Calorie Counting: More harm than good?
So weight loss is not always as simple as calories in and calories out. What’s more, calorie counting can be triggering and negatively impact mental health. In fact, studies have shown that calorie counting, and fitness tracking technology is associated with eating disorder symptoms.
Over recent years in fact, the use of calorie counting apps for weight loss and physical activity monitors has increased exponentially. In fact, most of us have built in pedometers in our smartphones and most likely have downloaded a calorie tracking app at some point!
Anecdotal evidence shows that such tracking devices can either trigger or maintain symptoms related to eating disorders. A group of researchers conducted a study in university students to examine the associations between the use of calorie counting and fitness tracking devices and eating disorder symptomatology.(2)
The study found that individuals who used calorie trackers had higher levels of eating concerns and dietary restraint, independently of BMI. Moreover, physical activity tracking was also associated with symptoms of eating disorders. These results suggest that for some individuals, calorie counting, and trackers of such nature may be doing more harm than good.
Calorie Counting and Eating Disorders
Furthermore, another study evaluated the implications of self-weighing and calorie-counting versus intuitive eating on eating disorder severity.(3)The researchers found that higher BMI, more frequent self-weighing, and calorie-counting, along with lower intuitive eating score were predictive of higher eating disorder severity.
Overall, engaging in self-weighing and calorie-counting behaviours appears to adversely affect eating disorder severity. It has been suggested that promoting intuitive eating may lead to more favourable outcomes. This would ultimately benefit both physical and mental health. So the truth about calorie counting for weight loss is that it may do more harm than good.
Motivational Support for Weight Loss
Calorie counting seems to have adverse effects on mental health. In addition, it also seems that people would prefer other methods of support to help them achieve their goals.
Many adults in most western countries today are considered either overweight or obese. This places them at increased risk of developing chronic health conditions such as heart disease, diabetes and multiple cancers.
Public health support for weight loss in several countries provides information about healthy diet and lifestyle. In addition, apps provide the opportunity for long-term motivational support.
A study looking at people trying to lose weight explored the problems, experiences and wishes that these individuals experience regarding weight management support. The subjects from this study unanimously agreed on the fact that waning motivation is a major issue when it comes to weight loss.(4)
Furthermore, they all expressed the desire for a motivational app that could provide support for weight loss and increasing physical activity. The participants stated that they disliked calorie counting apps as well as those that required a large amount of input from the user. There was a general consensus towards wanting behavioural elements such as goal setting and reviewing amongst the features of the app.
In addition, they expressed a wish for the app to be personalisable by adding picture reminders and choosing specific times for goal reminders.
Overall, it appears that there is a significant mismatch between what public health systems provide in terms of informational campaigns and weight-loss self-help resources on one hand, and what people want and need on the other hand. In fact, what people seem to want is motivational and autonomous online support.
Thus, this suggests that there is an opportunity to develop more effective self-help interventions. Instead of focusing on calorie counting, these would include motivational and useful information.
Aside from whether calorie counts are accurate, they are not always available for all the foods we consume. A typical example of this is home-cooked meals or food that we eat at a restaurant where they do not specify calorie counts on menus. In such instances, we have to rely on our own estimates. Unsurprisingly, according to research, these estimates can often be very unreliable. In fact, the data shows that people typically tend to underestimate the calories in foods, by an average of about 165 calories!(5)
Furthermore, our own unconscious biases can also significantly sway our calorie estimates. A common example of an unconscious bias is the “health halo” effect which leads us to dramatically underestimate the number of calories in foods that we either believe to be or are marketed as ‘healthy’.
Is Calorie Counting Accurate?
Calorie counters are created to calculate how many calories people consume daily. These are often in the form of wearable devices such as digital watches or even apps on your smartphone. Again, there is a large margin of error in such devices and at best, these values are simply approximations. The reason for their inaccuracy is perhaps that the calculations are complex.
In fact, they must account for how much energy we require for basic physiological functions such as breathing and circulation at rest. This is also known as our basal metabolic rate (BMR). In addition, these calculations must also account for how much we burn during daily activities and exercise, along with how much energy we consume through our digestive system, also known as the “thermic effect of food”.
Moreover, factors including gender, age, body weight and muscle mass also significantly impact the number of calories that an individual expends per day.
Therefore, due to the aforementioned reasons, we should not expect calorie counting to be effective as a weight-loss strategy, especially if used as a sole method of weight loss.
Further, as we reduce our energy intake and eventually lose weight, our bodies also undergo physiological changes. In fact, these changes occur to preserve our body fat stores and protect us from starvation as per our ancestral genes. Thus, this leads to a change in our metabolism. In fact, if person A weighs less than person B, person A will have a lower BMR than person B, thus burning less calories at rest.
Therefore, as we lose weight and weigh less along our weight loss journey, we burn less calories. This phenomenon is known as “adaptive thermogenesis”. In other words, our bodies become more “efficient” in their utilisation of energy from food.
Consequently, it becomes more challenging to lose more weight and maintain weight loss with the same amount of calories. This adaptive thermogenesis is a process we have inherited from our ancestors and it was essentially designed to promote survival in times of food scarcity and famines. Given that it is engrained in our genes, we cannot prevent it from occurring.
Lastly, our genes affect our weight and overall build. In fact, if two adults of different heights, weights and builds ate exactly the same foods and consumed the exact same calories, they would still look different to each other. So comparing yourself to other people is counterproductive because we are all unique and have different energy needs!
Overall, calorie counting should be considered with a grain of salt if it is something that you wish to pursue. The truth about calorie counting for weight loss is that there are so many other variables at play. Working with a registered dietitian is the most effective and safest way to achieve weight loss in a healthy and sustainable way.
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