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Counting Calories is a Ridiculous Way to Try to Lose Weight

It just Does NOT Work. We’ve all done it.

Dr. Jason Fung
7 min readMay 2, 2018


The calorie theory of obesity has been perhaps one of the greatest failures in the history of medicine. Given the number of excess deaths caused by metabolic syndrome, you could argue that it is a bigger disaster than World War II. It is based on a complete misinterpretation of the energy balance equation.

Body fat gained = Calories In — Calories Out

This equation, known as the energy balance equation is always true. So, looking at this equation, people then say something like ‘It’s all about restricting the calories you eat’, or ‘All diets work by restricting calories’. On the Calories Out side, you hear things like ‘You should exercise more’. This is the standard Eat Less, Move More approach. Doctors, even so-called ‘obesity experts’ and various health professionals say stuff like this all the time, but they’re completely wrong. The problem is that they don’t even know why they’re so wrong.

The energy balance equation (which, yes, is always true) does NOT support the Eat Less, Move More approach. Huh? Let me explain. You can also watch my recent video from NBC here.

Let’s throw some numbers into the mix to make things more clear. Assume the baseline situation of stable body weight (zero body fat gained or lost) and 2000 calories per day intake.

0 Body Fat = 2000 Calories In — 2000 Calories Out

Calories Out is not just exercise. This is composed of 2 things — resting energy expenditure, or basal metabolic rate (BMR) and exercise. If you assume zero exercise, an average BMR is 2000 calories per day. This energy is used by the heart, lungs, kidneys, generation of body heat etc. Note…



Dr. Jason Fung

Nephrologist. New York Times best selling author. Interest in type 2 diabetes reversal and intermittent fasting. Founder