If you have not seen part 1 take a moment to review it. So what is the key to weight loss anyway? Although there is a lot of press out there stating that “Calories do not count” and “just focus on eating healthy” the fact is that regulation of bodyweight and bodyfat (two different things!) are primarily controlled by the balance of energy you take in from food and beverages (calories) and the energy you use to maintain all your cells and fuel all movement. So why are people (including some very bright researchers as well) saying that calories don’t count?
First because a lot of research that is quoted was done WITHOUT controlling calories taken in and using participant recall to estimate calories taken in. Here is the problem with this – we are lousy at estimating calories taken in. In fact even trained dieticians frequently underestimate their calorie intake by 40%! Imagine running a business and underestimating your bills by 40%! In literally every case when food intake is precisely controlled or measured through a process using “doubly labeled water” (which can be used to measure food intake with 100% accuracy without having to measure and provide food) people do in fact lose weight based on calories in and calories out!
Second because there is confusion about a process that is built into every human being called “Metabolic Adaptation”. Simply put your body adjusts to any prolonged reduction in calorie intake (regardless of the type of diet!) by reducing resting metabolic rate. In addition if the reduction in calorie intake is really large your level of spontaneous physical movement will be reduced. This process is based on hundreds of thousands of years of humans living in a world where adequate food intake was NOT guaranteed and in fact people frequently were forced to not eat for prolonged periods of time. So the ability to reduce the body’s need for energy was a fundamental survival mechanism encoded in all our genes!
For example if you take a group of people of about the same height, weight, age, sex and activity level who require 2,000 calories per day to maintain their current bodyweight and drop their calorie intake to say 1,500 calories per day all of them will lose weight/fat initially. However within a 2 – 3 month span all weight/fat loss will cease even if they continue to eat exactly 1,500 calories per day and maintain the same physical movement profile because as you lose weight/fat the body ALWAYS responds by lowering resting metabolic rate. So unless you INCREASE physical activity ALL DIETS become less effective over time regardless of how “healthy” they are!
Stay tuned for part 3 and learn the difference between weight loss and fat loss!