Metabolic Makeover: A calorie is NOT a calorie

Written by Richard

Can you eat more and still burn fat?


Treating fat loss like a mathematical equation is an incredibly common mistake. Comparing calories in versus calories out is not wrong, its’ just not easily measurable. I’ve brought up this point many times in previous articles but it cannot be emphasized enough. The caloric value of food is tremendously difficult to calculate. In fact, manufacturers have a 25% acceptable margin of error in caloric content of food. To put this in perspective, in theory an extra 21 calories per day extrapolated over 10 years would amount to a weight gain of 20 lbs. If it was really just a question of balancing out an equation we would need to be extremely accurate (99.2% accurate to be specific!). Exercise energy expenditure is also very hard to measure. In order to get accurate measurements; sophisticated equipment is required. Calories in is everything you consume. Calories out is your metabolism (BMR/ RMR) and exercise.

Metabolism isn’t just about math.

Even with an obsessive amount of exercise (for example: 7 days per week, one hour each day of intense physical activity), the largest energy use in your body is still your basal metabolism.  This explains a set of counter intuitive observations.

A group of interesting study done in 1965, shows that caloric restriction causes fat loss in the short term, however the macronutrient proportions (Fat vs. Protein vs. carbohydrates) matter much more.  In fact, the subjects on average gained weight while eating a diet of 1000kcal per day when 90% of the content came from carbohydrates.  A third study in this series also showed that “Increasing calories by 30% triggered weight loss, just by changing the proportions of the macro-nutrients”.  That means you can eat more and still lose weight, Amazing!  It also means you can under eat and still gain weight, much less fun. A summary can be found here.


In last week’s post, I alluded to this experiment where Sam Feltham lost a few inches around his waist while eating over 5000kcal per day.  Sam was following a low carb, high fat diet.  He also did this experiment with high carbohydrates and gained lots of weight.


The take home message is that carbohydrates, specifically sugar and processed starches are more important to monitor and limit rather than total calories.  This is a quality not a quantity issue.

Here is an excellent lecture on alternative hypothesis for diet and weight relationship


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