Why Is Losing Weight So Difficult? (The Leptin Factor)

With a healthy dose of determination and a few altered lifestyle and dietary habits, you can ditch the additional body fat and approach a respectable level of body composition. However, when bitten by the training bug, you may reach a point when respectable is not good enough. So why is losing those last few pounds so difficult? Enter leptin – one of the key factors related to fat loss.

Leptin is a hormone that plays a key role in regulating energy intake and energy expenditure, including appetite and metabolism. It is one of the most important adipose derived hormones. That’s right - fat isn't simply just a storage tank for excess calories, it’s actually an endocrine organ, like a thyroid or adrenal gland, for example. This means that fat – in this case white adipose tissue – secretes hormones, and leptin is one of them. The more fat the fat cells contain, the more leptin is released. Think of leptin as a metabolism controller and a hunger regulator. It controls food intake and energy expenditure by acting on receptors in the hypothalamus. The absence of leptin (or its receptor) leads to uncontrolled food intake and resulting obesity.

This is nature at its finest. Your body is programmed to survive. On one hand, when food is available, leptin keeps you from adding too much fat mass. On the other hand, leptin responds to and defends against excessive body fat loss that might threaten survival or reproductive ability. Eat too much and metabolism speeds up to keep up. Don't eat enough and it slows down to keep you alive.

Leptin resistance is a condition in which the brain can't determine when body fat is at an appropriate level. The fat cells are sending leptin out to the hypothalamus to signal that fat stores are full. Leptin binds the receptors, but no downstream messages are sent. It's like knocking on the door when nobody is home. In spite of all the extra body fat mass, the brain perceives starvation and orders fat storage.

Here are a few tips to prevent leptin resistance and keep your metabolism humming:

- Get and stay lean

Don't "bulk up”. Stay close to target weight, and minimize body fat gain, then you won’t have to resort to extremes that put your body into survival mode to get lean.

- Cheat meals

When you go sub-maintenance calorically and get into a depleted state, adding in a cheat meal once per week can stop you from entering "perceived starvation." This will help prevent leptin resistance.

- Limit inflammation

Reducing inflammation increases leptin and insulin receptor.

- Don't go carb-crazy

High insulin levels cause insulin resistance, which causes increased inflammation. Insulin and leptin resistance are so intertwined that fixing one helps the other.

- Sleep

Sleep deprivation reduces serum leptin levels. In some cases, dysfunctional sleep can also increase leptin levels, leading to leptin resistance.

There are also several dietary supplements that can help fight leptin resistance – calcium, fish oil, taurine and acetyl-L-carnitine.