This hormone predominantly focuses on blood sugar levels, which typically rise whenever you eat (especially carbohydrates). The insulin levels in healthy individuals do not usually reach dangerous amounts.
Why we need it: When our blood sugar rises, it signals beta cells (unique cells in the pancreas) to release insulin into the blood. The insulin then binds to the cells, allowing glucose (sugar) to enter the cells and be used for energy. So, without insulin, glucose cannot leave the blood stream.
When a person is unable to produce enough insulin or they have become resistant to insulin, this hormone loses its ability to remove sugar from the bloodstream, therefore leading to diabetes. A type 1 diabetic has damaged beta cells, meaning that insulin cannot be created or stored. As a result, type 1 diabetics need insulin injections after their meals. A type 2 diabetic can produce insulin, but in insufficient amounts, leading to blood sugar build-up and insulin build-up. Diabetes can cause numerous health consequences including:
Kidney disease or kidney failure, requiring dialysis
Vision loss or blindness
Weakened immune system, with a greater risk of infection and more.
What to do: As the aforementioned problems are caused by insulin resistance, your goal should therefore be to increase your insulin sensitivity or at least maintain a healthy level. The most effective way is through maintaining a diet that is low in carbohydrates.
The hormone leptin is what tells you that you are full - it is your satiety hormone. So, whenever you eat, your leptin levels rise and your appetite starts to wane. But, what happens to the body if you are unable to produce leptin? Take a look at the rat on the left, in the above picture.
Why we need it: Weight loss and body fat are about more than just willpower. It is a combination of genetics and hormones. In a healthy individual, leptin tells the brain that they have sufficient fat stored away for when needed. If your stores are full, there's no point in eating more, so your appetite becomes suppressed. Many obese people tend to be leptin resistant. And once you become resistant to leptin, your brain cannot interpret the leptin signals as it should. This causes obese people to eat past the point of where they should be satiated.
What to do: Whether obesity causes leptin resistance or leptin resistance causes obesity is unknown. However, in both cases, it is a problem. Science however believes that the most likely causes are inflammation (which leads to neuron injury), genetic factors, lifestyle and diet. So, while not much can be done about genetic factors, diet and inflammation can be controlled.
Inflammation is usually a result of poor diet and a stressful lifestyle. Stress can lead to weight gain, therefore leptin resistance may occur due to inflammation. Eating a diet that is low in processed sugars (a major cause of inflammation), with adequate amounts of protein should improve your leptin sensitivity. Exercise and sleeping well also improves leptin's sensitivity.
While insulin works to remove excess blood sugar from the bloodstream, glucagon works to increase the amount of blood sugar when there isn't enough. And while insulin is created, stored and released by beta cells in the pancreas, glucagon is created, stored and released by alpha cells in the pancreas.
What to do: Glucagon doesn't get half as much of the attention that insulin gets, primarily because in order to become resistant to glucagon, you need to suffer from some sort of condition. For instance, if insulin levels are too high, they can block glucagon from being released. This can lead to hypoglycemia (low blood sugar) in certain situations. To prevent insufficient levels of glucagon, maintaining good insulin sensitivity should suffice.
Often labeled the 'stress hormone' cortisol plays an important role in your physiology.
Why we need it: When you feel stressed, your blood sugar levels tend to drop fairly quickly. During this process, glucagon will attempt to raise it and cortisol is there to help out. Cortisol is produced by the adrenal glands to accelerate protein breakdown and begin GNG (gluconeogenesis) - a process of making sugar from various byproducts, including those of protein. Cortisol also signals to fat cells, to start releasing stored fat to be used for energy.
So, while in the short term, elevated cortisol levels can be a good thing, in the long term, elevated cortisol can cause major problems. In fact, prolonged elevated cortisol can hinder long term memory, cause muscle wasting (telling the body to break down protein in order to make energy) and it suppresses and hinders the immune system.
What to do: Cortisol is predominantly affected by lifestyle not diet, which would include rest, low intensity activity such as walking and yoga combined with high intensity activity.
Known as the 'hunger hormone', ghrelin tells you when you are hungry. It therefore plays an important role in regulating energy and how it is used, therefore affecting how energetic you feel. When ghrelin is released, it is because your stomach is empty. It therefore signals your body to start preparing for incoming food.
Why we need it: Both ghrelin and leptin work together, regulating the overall long term weight of a person. Leptin tends to be more of a constant hormone, meaning that it is always present on some level. Ghrelin, on the other hand is more cyclical. As such, it's not possible to become resistant to ghrelin, however it can function abnormally. For instance, among obese individuals, studies have shown that ghrelin is not produced during sleep, as it is in a healthy, lean patient.
While it may seem like a good thing at first - as it would mean that we are less hungry upon waking, ghrelin is important for activating growth hormone production and energy use. So, a lack of ghrelin can leave you deprived of energy, thus contributing to remaining obese.
What to do: Ghrelin is affected by lifestyle and body fat percentage, rather than food's nutrition. Nevertheless, maintaining a healthy weight is arguably one of the best ways of having your ghrelin hormone function effectively.
This hormone, better known as the 'male sex hormone' is important for both genders. While men make use of it a lot more, women are still fairly sensitive to testosterone. In fact, it is used in the body to regulate sex drive and function, maintain and grow muscles, keep bones healthy and dense as well as grow hair.
Why we need it: If your testosterone levels are low, then you likely have a low sex drive, an inability to grow muscle significantly and weaker bones. But what causes low testosterone? One culprit is low-fat diets. In one study, patients on a low-fat diet for 8 weeks saw a 12 percent reduction in resting testosterone.
What to do: Include more vigorous exercise into your lifestyle, sprinting and heavy lifting in particular. Sufficient levels of vitamin D is also needed to maximize testosterone.