Our hormones play a large part in our fat-burning and storage mechanisms. The following eight hormones are the most important ones and I have tried below to summarise how they work together and how they affect our sugar & fat levels.
Insulin is known as a storing and locking hormone. High insulin levels cause extra sugar to be stored as fat whilst locking fat cells so they cannot be used for energy. A diet that includes sweets, processed foods and high in starches impacts on our insulin levels by raising it which increases the body’s fat stores and reduces its fat burning potential.
Glucagon is insulin’s opposite which means if insulin locks away fat glucagon can help burn fat. It works in the liver to help regulate sugar and fat usage. The insulin and glucagon ratio is a major determinant of whether you burn or store fat. In general, starches/sugar secrete insulin whiles protein stimulates glucagon, so adjusting the protein/carb balance favours fat burning.
This hormone controls hunger. As the level raises a hunger and craving message is sent to the brain. It is difficult to overcome this message with willpower alone and if you have had a history of yoyo diets and calorie restrictions your ghrelin levels will rise more regularly than if you had not, therefore you will feel hungry more often. Eating protein, fibre and doing intense exercise will help to blunt ghrelin’s message.
This hormone decreases our appetite and tells us when we are full. This is also one of the hormones that control the thyroid to stabilise the metabolism and use fat as an energy source. It is stored in fat cells, so whilst it should lower our appetite, the more fat cells we have the more leptin is released and our body adapts to it, therefore ignores its message to stop eating. We continue to eat and eat and eat and thats why some people become morbidly obese: their bodies never receive the message to stop
This is our 'fight or flight' hormone. When we are stressed we release adrenaline into the blood stream to help us deal with unforseen and potentially dangerous situations. When we are unable to utilise this adrenaline (by not exercising) and when it is released in the presence of high insulin and leptin levels the body switches its energy source to sugar. If we can balance out the body’s insulin and leptin levels, when adrenaline is released it will become a fat burning hormone as cortisol, testosterone and human growth hormone.
Is the Jekyll and Hyde hormone and can be your best friend or worst enemy when it comes to fat burning. Cortisol's primary functions are to increase blood sugar through the synthesis of no-carbohydrates, suppress the immune system, and aid in fat, protein and carbohydrate metabolism. It is also released in response to stress, lack of sleep can increase cortisol levels, as can caffeine. When cortisol is released in the presence of high insulin, low testosterone and limited human growth hormone it causes the body to store fat and use muscle stores as the predominate energy source. If it is released with large amounts of human growth hormone and testosterone it blocks muscle burning while enhancing the fat-burning effect.
Testosterone and Human Growth Hormone
These are building and burning hormones. These send signals to the body to become lean and muscular by working with cortisol and adrenaline to use fat as energy rather than stored. Working out with weights at high intensity will help to increase these hormones in the body (but ladies don't worry it doesn't mean you will start looking or behaving like a man).