There’s a common belief that weight gain is only caused by personal choices. Most people who have obesity can tell you that’s not true, but it’s an assumption we still hold onto as a society. Obesity is actually caused by several factors, and it can be reinforced by disrupted hormone signaling, especially with hormones like leptin and insulin. Read on to learn about how leptin can play a major role in long-term obesity.
Leptin is a hormone produced mainly by fat cells. When it’s working as it should, it tells the brain that the body has adequate stored energy, which helps regulate appetite and energy use. While it is impacted by fullness, leptin is not simply a “fullness hormone.” Its main function is to help your body maintain its current weight over time. Since leptin is stored in adipose tissue, obesity causes high leptin levels. This can lead the body to stop responding to leptin appropriately, leading to leptin resistance.
When you have leptin resistance, your brain becomes less responsive to leptin. This can make you feel a persistent hunger and reduced satiety when you do eat. It can also make weight loss difficult to sustain. This is because the brain is not registering stored energy signals effectively. The body can interpret this to mean you’re hungrier than you actually are or that you need to conserve energy when you actually have plenty of energy stored.
Insulin is a hormone made by the pancreas that helps regulate blood glucose and energy storage. Chronically elevated insulin and insulin resistance can lead to impaired leptin signaling, potentially contributing to leptin resistance. The relationship between these two hormones is complex and can run in both directions. High insulin is not the only potential cause, but recent studies have shown a link.
Similar to leptin, insulin does not come from food. The body produces insulin in response to the nutrients it receives. Meals rich in rapidly digested carbohydrates can raise blood glucose and stimulate insulin production. Protein also stimulates insulin, generally to a lesser degree than carbohydrates. Insulin sensitivity can be affected by factors like dietary patterns, physical activity, sleep and medications.
An increase in fat mass raises leptin levels, which can create an unfortunate feedback loop. With higher leptin levels, the brain becomes less responsive, so hunger and energy conservation persists, making it easier to continue gaining weight than to lose it. Insulin resistance can interact with this loop, making it more of a vicious cycle. In this way, it acts as one contributing factor to obesity among many, which can also include genetics, stress levels, sleep habits, health conditions and food access. With all of these factors combined, obesity can become self-reinforcing.
Leptin normally communicates energy sufficiency, but leptin resistance blunts that message. If you find yourself constantly hungry and tired, leptin resistance may be a factor. Getting plenty of sleep, exercising regularly and managing your stress levels can help you combat the effects of leptin resistance. When changing your lifestyle habits feels impossible or doesn’t help, you may consider seeking the guidance of a weight loss doctor. Remember, asking for help is not a sign of weakness—it just means you’re committed to living a healthier life!
