Hunger is sometimes just plain old, garden-variety hunger – your body’s way of telling you that it’s been too long since the last time you gave it some fuel. If this is the case, logic will generally drive your decision at the fridge door and you’ll reach for the leftover chicken. But other times, your hunger can be a craving for something else altogether.

Water

Has your body been telling you for the last three hours that it’s thirsty? Sometimes thirst is easy to ignore, especially if you’re on the go all day. Hunger is often thirst in disguise. Eventually your body gets so sick of its thirst signals being ignored that it changes up its tactics in order to get some hydration. Since you didn’t listen the first time around, your body decides to send you messages that you’re ravenously hungry and this usually has an end result of you consuming something – but possibly not something particularly nutritious. Many people will find they crave foods with high water content (such as fruits for example) when they’re thirsty, or salty food when they’re dehydrated. While there’s nothing wrong with satisfying these cravings sensibly, it’s a means to an end. Walking around dehydrated isn’t doing you any favors from a general health and performance perspective.

Sleep

Would you actually kill for a quick nap right now, but since it’s not really an option at 3:00pm on a busy workday, you’re after a quick energy fix in the form of food?A lack of sleep changes the way we experience hunger by way of two hormones: leptin and ghrelin. Ghrelin is responsible for signaling hunger and stimulating appetite, and leptin is responsible for signaling satiety. Lack of sleep has been shown to increase levels of ghrelin and decrease levels of leptin in your blood. So when you’re sleep deprived you’re likelier to be hungrier and less able to tell when you’re actually full. A good way to work out whether you’re actually craving sleep is to ask yourself whether you’d prefer to snuggle up under the duvet and doze off, or if you actually need food right now.

Relaxation

Similar to lack of sleep, stress also changes the way we experience hunger by changing our hormonal balance. Our body produces cortisol in response to a stressful situation. Cortisol not only been shown to stimulate appetite, but packs a double whammy and tells our body to store any energy that’s not needed immediately (that means fat stores). So next time you think you might actually be craving relaxation instead of needing fuel, perhaps consider a soothing cup of herbal tea and a few minutes of quiet time before you crack open the ice cream.

Emotional Expression

Most of us, at some point in time, have experienced emotional eating, otherwise known as eating your feelings. The science behind this emotional eating shows that consumption of certain foods (particularly sweet foods) sets off a chain reaction resulting in the release of serotonin, your “happy hormone.” When you’re feeling anxious, depressed, bored, and surprisingly sometimes even happy, you can end up delving into a tub of ice cream in an attempt to even out your hormones. Physiologically it might work, but the feeling of a bloated belly full of ice cream is probably not going to make you feel any better, plus the fact that you haven’t actually expressed the emotion that started this whole thing. It’s a tricky one because the last thing you feel like doing when you’ve had a terrible day is sitting down and actually dealing with your emotions. So it may be the perfect time to do something active that will give you the serotonin hit you’re craving, and deal with the underlying emotion when you’re riding the post-exercise high.

It sounds simple, but sometimes taking a few seconds to step away from the fridge, breathe, and actually think about what you’re hungry for will tell you a lot about your body, habits, and emotions. Not only is that going to help you get a long way towards your performance and body composition goals, but it will also help you avoid that disappointed, “Why did I do that?!” moment gazing at the empty ice cream tub.

The post What Are You Really Hungry For? 4 Things Other Than Food You Might Be Craving appeared first on Breaking Muscle.

But like with all other hormones, if we get too much leptin our cells will desensitize to the hormone and we develop dysfunction in the leptin pathways. This means the leptin signal telling us to stop eating and to stop storing more fat cannot be heard. This leads us to continually overeat and to store more body fat. The good news is that leptin sensitivity can be regained.

Leptin and Insulin

One way leptin sensitivity can be regained is through proper exercise. Leptin and insulin communicate with one another and work collectively with other hormones to control our energy balance. As insulin levels rise so do leptin levels. Exercise has been proven to increase insulin sensitivity. Exercise increases the need for the muscle cells to replenish lost fuel. Eating a diet that is too high in sugar can lead to excessive amounts of insulin being secreted. This can lead to insulin resistance, which means we will need even more insulin. Remember, that as insulin levels rise so do leptin levels. This is how insulin resistance induces leptin resistance. By reestablishing insulin sensitivity we will not need as much insulin in response to ingested glucose and as a result we will have lower leptin levels.

Leptin and Exercise

Exercise may be able to decrease leptin levels as well. In a study done on rats, leptin levels decreased following four weeks of voluntary wheel running.¹ This shows that exercise can play a critical role in reestablishing energy homeostasis. The problem is it needs to be done appropriately. Being chronically stressed or exercising too much or too intensely can yield some negative results. The reason for this lies in our fight-or-flight response.

Adrenaline, or epinephrine, is a major player in our fight-or-flight response. Adrenaline allows us to deal with physical and emotional pain. It also frees up the fat we have stored, making it an important piece to energy homeostasis. Adrenaline is released under stressful situations, but when we have too much adrenaline released (i.e. chronic stress) our cells will also desensitize to it. This makes it extremely difficult to release stored fat for energy. Also, under times of stress we get an increase in adrenaline and a decrease in leptin.² This can lead to overeating.

Exercise is a stressor and adrenaline is released during physical activity. If we are chronically stressed and over exercise we can further our adrenaline resistance. This will keep leptin levels low and can lead to us chronically overeating. Our major stress hormone is cortisol. Cortisol induces insulin resistance, so this is a double whammy on leptin levels. Over exercising can also cause increased levels of inflammation. Inflammation automatically induces insulin resistance. That’s a serious hormonal avalanche.

How Much Is Too Much?

So how do we know we are exercising too much? The answer is to listen to your body. If you are constantly sore, experience fluctuating moods, do not look forward to exercise, and are not making any new gains (or are even moving backwards), you need to scale back on the amount of exercise you are doing. The appropriate amount of exercise is going to be different from person to person. This is due to the fact that the amount of daily stress we are under varies by individual, as well as how well we handle that daily stress. Simply put, if you are not doing some form of active stress management then you are not managing your stress well.

The Lesson In Leptin

Leptin is an important hormone that controls how much body fat we store and how much food we consume. Through poor dietary choices and high stress levels we can develop leptin resistance. This can lead to increased fat storage as well as overeating. Exercise is a tool we can use to help restore leptin sensitivity. It works through increasing insulin sensitivity and by directly lowering leptin levels. When exercising we need to listen to our bodies because exercising too much can lead to adrenaline resistance, which lowers leptin levels and increases our risk of overeating.

Our knowledge of leptin is new discovery, having discovered it just nineteen years ago. Hopefully, as we understand its role in the human body with greater detail, we can devise more thorough plans to correct any issues associated with it. Studies are beginning to show that leptin plays a role in many different areas, including behavioral aspects and various diseases.

I will dive deeper into other roles that leptin plays in human function in upcoming articles. If you have questions about the function or management of leptin, please post to the comments below.

References:

1. Baba T, et al., “Reciprocal changes in leptin and tumor necrosis factor-alpha with exercise in insulin resistant rats.” Research Communications in Molecular Pathology and Pharmacology (2001). Accessed on October 25, 2013.

2. Rayner DV and Trayhurn P. “Regulation of leptin production: sympathetic nervous system interactions.” Journal of Molecular Medicine (2000). Accessed on October 25, 2013.

Photos courtesy of Shutterstock.

The post How Leptin Helps Us Avoid Getting Fat appeared first on Breaking Muscle.