A weight loss plateau often occurs because the difference between energy intake and energy expenditure gradually balances. The human body must restore energy balance in order to survive. Imagine the potential for human survival if we kept losing weight because we couldn't find enough food (energy intake) when roaming the land thousands of years ago!

Our body needs these natural physiological mechanisms to help maintain energy balance relatively quickly.

The Process of a Weight Loss Plateau

In order to lose weight, we need to create a negative energy balance or a calorie deficit, this is fact. The number of calories we cut from our intake needs to be sufficient enough in order to see some results fairly quickly. So if we begin a new diet by cutting our calorie intake by about 500 per day we will lose weight over the course of a week or two.

During a calorie deficit our body still requires the same amount of energy thus, it starts using up energy stores to make up for this 500 calorie deficit. However, as our body inevitably uses up extra proteins for energy AND to maintain normal protein synthesis, we end up with a net loss of total protein. This results in a gradual loss of lean muscle, and this is the start of a lowered metabolism.

In fact, protein (muscle) loss may go unnoticed when looking in the mirror because the body will take it from other, less priority areas and not just from our skeletal muscles. The stomach is a classic area where protein is broken down for use, as there's less need for a large stomach capacity because we have lowered our food intake. Ever noticed how we can no longer eat those big meals we once used to eat before dieting?

A Decreased Metabolic Rate

The initial weight loss slows down as the body progressively loses further lean mass, this continues until the point where a calorie deficit is so minute that it no longer has any effect on fat loss. Our metabolism has decreased and we have reached that dreaded weight loss plateau. What it means is our body has gradually adapted to match our new energy intake, and we now require less energy to maintain the new weight. This process was ideal many years ago when our ancestors roamed the land, but unfortunately for us, this is a part in dieting where we cannot seem to lose any more weight. For this reason we need to view any long-term weight loss in different stages.