Leptin is a hormone made by fat cells that was first discovered in 1994 by Jeffery Friedman. It is the original “hungry hormone.” Like all hormones, leptin is a chemical messenger. When it comes to leptin, the message leptin sends is “I’m full.” Leptin is produced by fat cells, travels through the blood stream and then works in appetite centers of the brain, signaling feelings of fullness. When leptin levels are low, you feel hungry and are motivated to seek out food.
People with leptin deficiency are hungry all the time and very overweight. They can take leptin injections and lose lots of weight without diet or exercise. The problem is that leptin deficiency is extremely rare. In my career, treating thousands of overweight and obese patients, I’ve never seen one case of leptin deficiency (neither have any of my colleagues.)
So if leptin deficiency is so rare, why all the excitement about this hormone? It turns out that most people who are overweight or obese have dysfunctional leptin. In fact, their fat cells make huge amounts of leptin. But, since the leptin isn’t working properly, the massive amount made is still insufficient for suppressing appetite, leaving a person feeling hungry all the time. In effect, even though leptin levels are high, since it doesn’t work properly, the body thinks leptin is low. With leptin resistance, the brain isn’t getting the message that it is time to stop eating, time to lose weight. Leptin resistance results in the brain protecting the body from perceived starvation, even in people who are profoundly overweight.
The following are symptoms of leptin resistance.
- Do you feel hungry all the time?
- Do you have unexplained weight gain?
- Is your weight slowly creeping up over time?
- Do you have cravings for comfort foods, fast food or high calorie foods?
- Are you not hungry for breakfast or skip breakfast?
- Do you overeat at supper?
- Do you have excess body fat?
- Do you have unusual eating patterns, or does your diet vary significantly from day to day?
- Does weight loss stall after losing only 5-10 pounds.
- Do you have insulin resistance, metabolic syndrome, prediabetes or diabetes?
- Do you have arthritis, asthma, lupus or allergies?
- Do you have high blood pressure or elevated cholesterol?
- Do you have poor sleep, disrupted sleep or short sleep?
If you answered “yes” 3 or more of these questions, there is a good chance you have leptin resistance.
Leptin resistance means that your brain thinks you are starving when the reality is just the opposite. Dysfunctional leptin drives appetite and especially cravings for high calorie foods and junk foods. The brain is doing anything it can to prevent starvation.
Leptin resistance also causes lower metabolism and can lead to a host of other hormone problems like insulin resistance, type 2 diabetes, polycystic ovary syndrome, low testosterone (in men) and thyroid problems.
How do you fix leptin resistance?
Next week, I’ll show you ways to make your leptin work better and more efficiently so you can lose weight permanently.