Overview
If the goal is permanent weight control and improved health and wellness, Calories In Calories Out almost always does not work without extreme measures such as lifelong medications and major surgery. If you believe in the Calories In Calories Out model, the fault of obesity and metabolic disease lies with the person who fails to maintain the calorie balance.
But, Calories In Calories Out fails because the body tricks you into thinking there is a calorie deficit when there is not one. There is a complex hierarchy of calorie storage systems in the blood, muscles, and liver, each released and replenished over different time periods. Calories In Calories Out models typically base everything on a daily balance. This is where things go wrong.
In a Calories In Calories Out diet, each day you think you are running a deficit, you make up for it by drawing down calories from your muscles. Then, when you go out for your weekly reward or otherwise cheat, you replenish the stored calories in your muscles. The result is you are not running an overall deficit at all, with hunger fighting you all the way.
Hunger and satisfaction (also known as feeling full) are very complex human systems with many components and variables that are only now nearly understood. But one of the most significant determinants of feeling full is when an ideal-sized food bolus enters the bioreactor from the stomach. When you eat the right amount of food at the right pace, the stomach takes about 30 minutes to make the food bolus and move it into the bioreactor. That's where and when one of the most potent sensations of satisfaction occurs. This is how you eat the right amount.