What Is Leptin?

Leptin is a hormone that plays a crucial role in regulating energy balance and appetite in the body. It is produced by fat cells and released into the bloodstream. The primary function of leptin is to communicate with the brain, particularly the hypothalamus, to signal the amount of fat stored in the body. This, in turn, influences energy expenditure, food intake, and metabolism.

When fat cells increase in size, they release more leptin, signaling to the brain that the body has sufficient energy stores. This signals the brain to reduce appetite and increase energy expenditure, helping to maintain a stable body weight. Conversely, when fat stores decrease, leptin levels drop, signaling the brain to increase appetite and decrease energy expenditure, promoting food intake and fat storage.

What Happens When Leptin Is Out Of Balance?

When leptin is out of balance we can experience something called leptin resistance. Leptin resistance is when leptin cannot communicate properly with your brain to tell you how much energy is stored on your body. Leptin is supposed to dock on the hypothalamus while we are sleeping and gives the brain a download of how much energy we have on our bodies so our metabolism/energy expenditure for the next day is appropriate. We can have high or low leptin levels and have leptin resistance/dysregulation that leads to a number of symptoms and health issues.

Here are some common symptoms/signs of leptin resistance:

• Inability to lose weight
• Increased appetite
• Strong food cravings (especially for sweets after meals)
• Cold body temperature or have a hard time regulating your body temperature
• Hair loss
• Irregular cycles
• Infertility
• High inflammatory markers (CRP)
• High reverse T3 levels
• High blood pressure

You can do a blood test to understand your leptin levels. I discuss this more in my Patreon bonus episode, you can sign up for my Patreon here.

The major contributors to leptin resistance are:

1. Light exposure and circadian rhythm (leptin follows a circadian pattern when released)
2. Food intake (restrictive eating, under eating, overeating, etc.)
3. Stress (cortisol can impair leptin’s ability to communicate with the brain)

Leptin is one of those hormones that impacts so many areas of our health. I think about thyroid and how that impacts so many body systems, leptin is similar. The more you learn about leptin the less surprised you will be to learn exactly how many aspects of our health leptin touches.

Leptin is involved in:

• Metabolism
• Hormones (sex, stress, and thyroid)
• Immune system function (increased risk of autoimmune conditions)
• Energy balance
• Fertility & reproductive function

Do you want to get started on improving your leptin resistance? Here are some great resources below that address light exposure, nutrition, and stress.

• light, your circadian rhythm, & your hormones with carrie bennett
• Nourishing Nutrition Foundation
• a holistic approach to optimizing cortisol levels

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