Anybody who is serious about their nutrition and training knows of hormones in our body such as testosterone or IGF-1, which helps us build muscle and grow stronger, or melatonin which helps us sleep better. But one hormone which is just as important for all health conscious individuals has never gotten the attention it deserves: Leptin, also known as the starvation hormone. Leptin controls our hunger and satiety. Some nutritionists believe that leptin is more important than other hormones related to exercise and diet since without a healthy level of hunger/satiety it would be exceptionally easy to over or under eat. In this article I will be discussing this hormones function in our body as well as how to control it, making losing weight an easier process for anybody!
How Does Leptin Work?
Discovered in 1994 (relatively new compared to other important hormones), leptin is produced in adipose (fat) tissue. This means the more fat cells an individual has, the more leptin is released on a daily basis. Put simply, leptin has receptors in the hypothalamus (a small section of the brain). When you eat a filling meal, leptin is produced in your fat cells, and is sent to the receptors, which tell your brain that you are full and no longer need to eat. This effectively speeds up your metabolism until all the food is digested. Conversely, when an individual is on a diet eating below their maintenance calories, the level of leptin in the brain is much lower. This is why many are chronically hungry on a diet, as the low levels of leptin being sent to your brain tells your body it’s starving and causes you to crave food, usually leading to binge eating.
In recent years many have hypothesized that overweight and obese individuals aren’t the way they are due to simply eating too many calories, but instead as a result of something called leptin resistance. Little is known about this since leptin itself has only been really studied in the past couple of decades, but many believe it is related to insulin resistance. What we do know about leptin resistance is that even though overweight individuals produce more leptin than those of healthy weight (as a result of having more fat cells), the signals are not getting to the hypothalamus. Meaning that even though individuals are eating their brain isn’t telling them to stop, which leads to overeating and a slowed metabolism. This spells trouble for anybody trying lose weight, as their bodies are constantly hungry and telling them to eat no matter how full they really are, leading to more weight gain and short lived diets.
Controlling Leptin Levels
There are two types of issues associated with leptin:
✗ Individuals who are overweight
✗ Individuals who have a very low body fat
The first situation is tricky, as we don’t quite know what causes leptin resistance. But we do know of steps that can help reduce it, effectively reducing cravings and a chronically slow metabolism.
The first and most important step includes counting your calories, to see how far above your maintenance you are, and making you aware of everything you eat including little snacks between meals. Simply counting every calorie you put into your body will help you subconsciously eat less. While it doesn’t have to be fast, the next step would be to slowly reduce your daily caloric intake, at around 100-200 calories a week till you are losing around 0.5-1 pound a week. This should also be a daily priority, to weigh yourself first thing in the morning before breakfast and keep a log of how much weight you are losing a week.
Once you are losing a consistent amount of weight a week, your calories do not need to be lowered any further. Eventually your fat loss will plateau, and if you haven’t already, this is the time to create a consistent exercise routine you can follow at least a few times a week. By now your insulin and leptin resistance will have decreased significantly, meaning less craving as well as a new appreciation from being full on less food. Of course more steps exist revolving around eating healthier, weight training, and optimizing all your macronutrients. But those can be learned from most other diet programs and articles as I don’t want to spend too much time on basic nutrition now.
The first situation is specifically for those who are leptin resistant and are constantly hungry even with elevated leptin levels. The second situation I will discuss involves those who aren’t getting enough leptin in the brain do to extreme dieting. Whether it be a bodybuilder in sub 5% body fat, or an anorexic individual, this situation can be just as harmful as the first. When in a large calorie deficit most positive hormones in our body tend to decrease. Low levels of leptin brought on by very few fat cells can have many chain reactions in the body that are not very favorable.
Without proper stimulation from leptin receptors the metabolism rarely leaves starvation mode, causing the body to hold onto whatever fat stores it has left (anything below 8-12% body fat for men is not considered enough for proper health). What this means for a bodybuilder trying to get past that 6% body fat plateau is that it simply won’t happen as long as their metabolism is extremely slow and holding onto its fat stores. The other big issue comes in the form of cortisol, which stays chronically high as long as the body is in starvation mode.
What most don’t know about the stress hormone cortisol is that its primary purpose is to keep us awake, in fact it is at its peak first thing in the morning to try and help us get up (unless stimulants are your go-to). Put this all together and what do you get? An individual who is always tired yet can’t sleep at night, fatigued, hungry and overall more stressed out all because of low leptin levels.
Lucky for you the solution to this comes in the form of food! More than likely most of you reading this article implement a weekly cheat meal or refeed day to help curb your cravings and kick start your metabolism during a diet. And now you know why! By increasing your caloric intake temporarily your body can produce and release more leptin which can then bind to your leptin receptors, effectively telling your body you are no longer in starvation mode and raising your metabolism. The other positive from doing this comes in the form of less cortisol being produced, meaning you will feel more energized and sleep much better.
Take Home Message
With so much attention going towards hormones like testosterone and cortisol, we usually forget to take a step back and see what hormones affect those hormones. Leptin is one such casualty which is rarely talked about even though it is one of our most important hormones. Leptin is evidence of how simple calories in and calories out doesn’t explain the whole story when it comes to obesity and starvation. If you noticed most of the information I laid out on how to control leptin is similar to most weight loss steps or metabolism balancing steps, it’s because they are the same! The only difference is now hopefully you can understand how and why you need to do these things to prevent a broken metabolism as well as how to limit cravings.