“Insulin” and “insulin resistance” have been the weight loss buzz words for some time now and rightfully so. Insulin is a hormone that dictates fat storage and has a host of other important functions in the body. However, leptin, a close relative to insulin, is the new “weight loss” hormone on the scene.
What is Leptin?
Leptin is a hormone that is secreted by the fat cells and sends signals to the hypothalamus. If one has sensitive leptin receptors the body responds with satiety (you feel full) after a meal, and you stop eating. In healthy people, more body fat means higher leptin levels and therefore decreased hunger. This function allows the body to burn its fat stores. In people who have low body fat or are in a time of famine, leptin levels decrease and the brain signals the body to eat more and they feel hungry all the time.
When one loses weight quickly, via weight loss surgery or crash dieting, leptin levels drop dramatically. This increases hunger and cravings and decreases thyroid function (by increasing the formation of reverse T3) and metabolism which encourages weight gain. This is one of the reasons that yo-yo dieting doesn’t work.
Leptin also controls reproduction, puberty, immunity and libido. Leptin levels might explain why underweight women lose their periods and overweight kids reach puberty earlier.
If the amount of leptin is proportional to the amount of body fat we have, why do overweight people still feel hungry, overeat and experience cravings? That’s where leptin resistance come into play.
When frequently exposed to leptin, much like with insulin, the receptors being to lose sensitivity and the brain stops listening to the signals being sent. The body becomes leptin resistant and, even though large amounts of leptin are being released, it thinks you are in a period of famine and increases your appetite and cravings and slows down metabolism. It eventually takes more and more leptin for us to feel full. The body can also become leptin resistant in response to prolonged periods of elevated blood sugar. This means that people who are insulin resistant are more than likely also leptin resistant. High leptin is also linked to high blood pressure and metabolic syndrome.
Factors That Influence Leptin Resistance
As I mention, excess weight and constant exposure to leptin results in leptin resistance. However, there are several other factors that can contribute to this issue.
Fructose, the sugar found in fruit and in many sweetened and processed foods, has been found to cause leptin resistance by silencing the leptin receptors response. It is also thought to impair leptin’s ability to cross the blood-brain barrier due to an increase in triglycerides in the blood. This means that circulating leptin levels remain high but their communication with the hypothalamus does not happen.
Since insulin resistance and leptin resistance are closely related, eating too many refined carbohydrates (or too many carbs in general) is a contributing factor, as is overeating. Basically, eating a diet high in sugar and processed foods increases fat storage and insulin level, which then cause constant surges of leptin and eventual leptin resistance.
High stress levels can play havoc with blood sugar and encourage poor food choices and overeating. Similarly, lack of sleep and over-exercising put stress on the body and also plays a role in leptin resistance.
What Can You Do?
You can restore your body’s sensitivity to leptin by adopting several lifestyle changes. Like with all healthy changes, they need to be practiced consistently.
• Avoid fructose in the form of excessive fruit intake, dried fruit intake and packaged and sweetened products. Cut back on fruit intake initially.
• Get to bed by 10pm and aim to get 8 hours of sleep per night. This will help to lower stress hormones and help to prevent overeating.
• Don’t severely restrict calories or attempt any crash diets.
• Avoid processed carbohydrates, processed food and sugar
• Start your day with some protein and fat. This can be the form of eggs, leftover meat and vegetable or a smoothie with coconut oil.
• Try to have dinner 3 hours before bed and go 12 hours between dinner and breakfast to give your hormones a rest. You can still consume water and herbal tea during this “fast”.
• Do gentle exercise in short increments instead of endurance or cardio exercise.
• Eat more Omega-3s in the form of fish, grass-fed meats and chia seeds.
• Avoid omega 6 seed oils and damaged fats.
• Adopt some stress reducing habits like meditation or yoga.
Always remember that you are responsible for your health and well-being and if you want to lose weight (or stay slim) healthily, you can.