HomeNewsGuidesReadsPodcastsTRANSFIN. EOD
  1. Guides
  2. Advice

Count Your Calories: Is "Calories In, Calories Out" A Weight Loss Tip or a Myth

Director Cardiology, Fortis Escorts Hospital
May 12, 2019 5:04 AM 5 min read

The Amercian doctor and author LH Peters in what was perhaps the first ever book on nutrition Diet & Health: With Key to the Calories proclaimed:

“You may eat what you like… but count your calories!”

Published in 1918, and the first one to sell over a million copies, Diet and Health led to a mathematical understanding of obesity - the so-called CICO hypothesis (Calories in-Calories out).

A relatively simple concept which is easily understood by most:


One gets fat if one eats more and/or exercises less than is needed according to one’s height and age.

In order to lose weight, all that one needs to do is to reverse this equation i.e. Exercise more and eat less. This seemingly simple process has been followed, and is still sworn to by millions of individuals worldwide in a bid to lose fat and become fit. However...mostly in vain.


Count Your Calories


Studies over the last century have shown consistent results. Most serious dieters lose 5-10 kg in the first 3-6 months, after which their progress plateaus, followed by a slow regain of the lost weight (roughly 90% of the dieters regain at least half of their lost weight within 2 years; many of them even more). As most succumb to inertia, leading to lethargy and overconsumption, they remain overweight/obese. It would be worthwhile to ask why efforts of millions of humans and countless scientists failed to crack this seemingly straight forward task?

As Sherlock Holmes said to his friend Dr. Watson, “…when you have excluded the impossible, whatever remains, however improbable, must be the truth.” This might leave us with an uncomfortable truth - there must be something wrong with the CICO hypothesis.

A Calorie (or a Kilo calorie-kcal, or 1000 calories-cal) is a unit of heat-defined as the amount of energy needed to raise the temperature of 1 liter of water by 1° C. Wilbur Atwater calculated the energy content of foods in the late 19th century, and reached the conclusion that the energy content of carbohydrates and proteins is approximately 4 kcal/ g, while that of fat is 9 kcal/g. The average American adult was thought to need about 2000 cal/day for females and 2500 cal/day for males. The average calories needed to be burnt to lose 1 lb weight was estimated around 3500 cal (~7700 cal for 1 kg). This led itself to an easy interpretation - eat 500 calories less per day, remain active, and one should lose 1 lb per week (or 1 kg every fortnight).

This should be easily achievable by any dedicated dieter, and obesity should be rare. The facts, however, are mind boggling. Obesity has multiplied over 3-fold in the last 40 years, diabetes by 4-fold, and heart diseases have become mankind’s biggest scourge in this period. So, what are we missing?

What Are the Problems with Calculations of Calories Consumed?

  1. The calorie concept does not differentiate between nutrients themselves, meaning that the calories from sugar, butter and meat have the same response once digested. However, we now know that while carbs are easily digested within 2-3 hours, proteins take over 6-8 hours, and fats even longer (8-12 hours). This means that not only does one remain full for a longer period after a protein and/or fat-based meals, but also burns more calories in digesting them as well. This shows that eating and digesting are more complex compared to the simple math given above.
  2. The calorie concept also does not differentiate between the sources of nutrients, assuming all to have similar effects when eaten. For instance, all carbs are treated similarly, whether simple sugars, starchy vegetables like potatoes, or fiber-rich salads. While sugars are digested easily and lead to an early peaking of blood sugar levels, potatoes are metabolized much more slowly, even though ultimately even they get converted to simple glucose molecules. And fiber is indigestible, so has practically no calories (as the few calories that the food containing high fiber releases are used up in digesting them).
  3. It also does not account for the effects of cooking upon foods. Chopping and cutting food items simplify the work of digestion, as does cooking, by breaking down food into an easily digestible form, making the calorie content higher. Simply cooling a food after cooking and reheating it lowers its calorie content somewhat, making it very difficult to count the exact amount consumed.

What Are the Problems with Calculating Calories Burnt?

The other side of the CICO hypothesis is fraught with similar complications. Excluding young athletes, one cannot exercise enough to lose weight consistently or even keep it off, if one is not watching one’s diet. For instance, it would take an average adult 3-4 hours of brisk walk to burn the calories contained in a scoop of ice cream, a piece of chocolate, or the friendly samosa.


Count Your Calories

  1. For a normal healthy adult who is not into heavy running or weightlifting, the maximum amount of energy is consumed in unconscious non-    exercise related activities like digesting food, regular working of the organs, especially the brain, and minor home and work-related activities.
  2. The calories used in different exercises are dependent upon a lot of factors-age, body weight, current level of fitness and ambient temperature, among others. It is notoriously difficult to estimate the calories burnt in any activity, and the digital monitors on treadmills don’t really help.
  3. Metabolism acts differently in different people, which is why some people rarely gain fat, while others struggle to lose it despite eating much less. This upholds genetic factors (some of which are under research presently) which determine how many calories are taken up and how many are passed out undigested.

Hence even if the CICO is a valid hypothesis, it is a rather complex calculation with many imponderables. If one were to eat the equivalent of just 20 calories extra per day, one would gain about 1 kg every year, everything else remaining the same. Also, one rarely sees the predicted results within expected time. Eating 500 calories per day less than usual for 1 month doesn’t bring about a weight loss of 2 kg, hardly 1 kg or so. And most people feel tired, often listless, lacking in energy and the drive to exercise, and dream about splurging on their favorite dessert; which they do, sooner or later. And that too lasts a few months; soon there is a plateau followed by a slow regain.

So, do calories not matter at all? Of course, they do. But not in the way people think!

More on this next week.

This is a recurring column published every Sunday. Click here to view my other articles on health, nutrition and exercise. 

(We are now on your favourite messaging app – WhatsApp. We strongly recommend you SUBSCRIBE to start receiving your Fresh, Homegrown and Handpicked News Feed.)