How the Caloric Balance Affects Weight Loss

Trying to lose weight and looking for the simplest possible solution?

Achieve a caloric deficit. In simple terms, eat fewer calories than you burn. 

Seriously – that’s all it takes. However, achieving a caloric deficit that is sustainable for your lifestyle and doesn’t cause negative hormonal disturbances may be a bit more complicated. The complexity stems from the fact that the ideal number of calories you should eat daily is highly individualized and dependent on your metabolism. Eating more than this target will cause your calorie deficit to shrink and your weight loss to evaporate. Eating less than this target will cause your deficit to swell and potentially cause serious hormonal imbalances that ultimately lead to the dread weight loss plateau. Let’s discuss it in a little greater detail.

What is the Caloric Balance?

The caloric balance is the number of calories you consume from food and beverages each day vs. the number of calories you burn which can be categorized into three groups. 

• Calories you burn to keep your body alive (i.e. basal metabolic rate)

• Calories you burn to move (i.e. workout and daily movement) 

• Calories you burn to digest food (i.e. thermic effect of food). 

Being in a positive caloric balance means that the calories you eat are more than the calories your burn. This will inevitably lead to weight gain as the excess energy will turn into energy reserves for the future (e.g. fat or muscle tissue).  

Conversely, being in a negative caloric balance means that the calories you eat are fewer than the calories your burn. This will inevitably result in weight loss as the energy deficit has to be covered by using some of your body’s energy reserves (e.g. fat or muscle tissue). 

Arguing against positive and negative caloric balance is the equivalent of arguing against the Second Law of Thermodynamics, one of the laws in our universe dictating that energy cannot be destroyed or created but can only be transformed from one form to another. In the case of our body, energy surplus from food (e.g. eating more calories than burning) must be converted into energy stores whereas energy deficit from food (e.g. eating fewer calories than burning) must be covered by using some of our energy stores. 

But everyone says it’s not about calories in, calories out!

Determining the right number of calories you should eat isn’t easy because the number of calories you burn is highly individualized and dependent on your metabolism. Specifically, studies have shown that smartwatches are on average 25% off whereas predictive equations can be as much as 35% off [1], [2]. This means that if your true total caloric burn for the day is 3,000 kcal, a wearable device or equation will off by roughly 750 kcal. To achieve healthy weight loss, you would typically aim for a 500 kcal deficit meaning that you should be eating 500 kcal less than what you burn. However, an error of 750 kcal in calorie burn makes it impossible to determine your food intake such that you land at a 500 kcal deficit with a high degree of confidence. 

The challenge of measuring human metabolism gave fertile ground to countless theories and hacks promising effortless weight loss. Calories became a taboo of the weight loss industry which sought to provide a promise of weight loss through other approaches that didn’t focus on calories. Some of the most popular ones include the keto diet, the carnivore diet, the Atkins diet, forms of high carbohydrate diet, etc.  

What’s important to note is that any one of these diets can work or fail. What determines failure from success will forever be calorie balance. For example, following a keto diet while eating more than what you burn will cause you to gain weight. On the other hand, following a keto diet while eating less than what you burn will lead to weight loss. 

Science has unequivocally now shown how different types of diets can yield the same results. A recent landmark study conducted at Stanford University followed 609 individuals for 1 year and proved that there was no difference in weight loss between the group following a low carb diet with the one following a high carb diet [3].  

Why precision matters

No matter the type of diet you follow, a caloric deficit is the only way to achieve weight loss. At the same time, however, a calorie deficit is an abnormal state for the human body that can cause series of hormonal imbalances with long-term negative health effects. Some of these hormonal imbalances are responsible for the dreaded weight loss plateau. A calorie deficit that’s too big or lasts for too long can perturb the balance between leptin and ghrelin, two hormones responsible for regulating how “economical” our cells are in burning calories. In simple words, when too big, a calorie deficit can cause our cells to burn fewer calories than normal, a state we typically refer to as “slow” metabolism.

One of the most famous and well-documented cases of excessive calorie deficits that caused a severe metabolic slowdown and led to weight regain is that of the TV Series 'Biggest Loser'. Due to months of extreme dieting participants experienced a tremendous reduction in their metabolic rate which caused them eventually regain the weight they lost despite following a normal diet following the show. After the show, their bodies were burning significantly less compared to what was normal for their age, gender, and weight and so even a healthy diet would mean eventually lead to weight gain. What’s most important that these metabolic changes persisted for years after the show [4]. 

Analyzing the Biggest Loser aftermath shed light on the biggest myth surrounding weight loss, that diets fail due to lack of willpower. In fact, several studies have now shown that a slow metabolism is responsible for 90%+ of failed weight-loss attempts [5]. 

Conclusion

It’s an undeniable fact that for most of us one diet works better than the other. That’s because our preferences, digestion, lifestyle, and habits make it easier for us to achieve a caloric deficit by eating certain foods while avoiding others. 

This, however, should never turn our attention away from the caloric balance which will ultimately determine whether we are going to gain or lose weight. Keeping an eye on your calorie deficit won’t just ensure short-term success but will also protect you from long-term hormonal disturbances that can make weight management a lifelong challenge.