Both research and everyday observations indicate that while weight loosing your metabolism slows down. This is an adaptive response of the body to a situation in which calorie consumption does not cover daily requirements. The result is slowing down of the progress and sometimes blocking any completely, which of course is frustrating and kills your motivation. In such a situation, many people try to go drastic and deepen caloric restriction which does not always produce the desired effect. A much better way is to use the tricks that allow to outwit your body and accelerate metabolism.
Why metabolism slows down during weight loss?
Human body is a complex machine improved consistently in the toughest conditions for millions of years of evolution, as a result of which unique mechanisms have been developed that adapt your organism to variable food availability. Due to the specific requirements of our energy-consuming gadget: that is the brain, preserving maximum flexibility of energy management turned out to be one of the highest priorities. In practice, these adaptive mechanisms allow extremely efficient energy collection during caloric surplus and very sparing energy expenditure in the time of caloric deficit. Unfortunately, what allowed us to survive at times variable availability today has become the curse that makes it extremely easy to gain weight and particularly difficulty to get rid of fat reserves.
While slimming you put your body into a state of energy deficiency forcing it to delve into fat reserves. The result is a progressive decline in fat, which obviously gives you satisfaction. Unfortunately, due to the established body adaptation mechanisms your organism tries to adapt to the situation at all costs and reduces energy expenditure, whether by reducing the desire for physical activity (including spontaneous implementation of unplanned activities) or by lowering thermogenesis that is heat production. What underlies these relationships are, of course, hormonal factors, namely the activity of hormones such as leptin, ghrelin, cortisol, thyroxine and triiodothyronine.
Is metabolism slowdown imminent?
Theoretically, metabolism slowdown is a natural consequence of the introduction of a diet with negative caloric balance. In practice, however, it may happen that appropriate qualitative and quantitative selection of food does not reduce the rate of metabolism, but actually results in its acceleration. This happens especially in obese people whose significant excess of fat tissue led to a specific metabolic downfall, impairing the functioning of mechanisms controlling collection and expenditure of energy. In such situations, there is a very intriguing phenomenon in which with every lost kilogramme the metabolism speeds up, energy demand is growing and you need to systematically add more calories to your diet.
However, such cases must be regarded rare, or at least should not be treated as a rule. And even in situations when these phenomena occur, they are limited in time and after some period there comes a point where the rate of fat loss is slowed down markedly. And on this occasion, I would like to draw attention to ways of overcoming this deadlock, accelerating metabolism and increasing fat burning.
To understand leptin
In order to understand the mechanisms responsible for slowing down your progress during weight loss you should pay attention to the unique properties of leptin. Leptin is a peptide hormone secreted mainly by adipose tissue, its concentration in blood is clearly correlated with the level of body fat. This adipokine has extremely broad spectrum of activity. it influences different tissues, organs and systems, has both direct influence on the organism and through the sympathetic nervous system. Leptin also participates in the regulation of many body functions, including functioning of the immune, circulatory and reproductive systems. But we are particularly interested in the impact it has on the functioning of the energy management.
You should know that leptin has the ability to influence the mechanisms responsible for the control of appetite. Thanks to the circulation system it reaches the brain where it binds to its receptors in the hypothalamus and regulates the activity of hormones such as neuropeptide Y (NPY), Proopiomelanocortin (POMC) and a corticotropin-releasing hormone (CRH) which is not going to be described more broadly here. It is worth to note that the result of this relationship is reduction of appetite which leads to smaller food intake. Most important in the context of the interesting aspects is that leptin regulates not only energy consumption but also its spending, and this way affects the metabolic rate, which is related in large part to leptin's impact on the functioning of the hypothalamic-pituitary-thyroid axis.