Written By: Charles D. Shively, PhD, RPh
Perhaps surprising is that an individual’s weight actually triggers why we get hungry. Hunger “pangs” cause the forced interplay of two hormones: leptin and ghrelin and the subsequent influence of another hormone (insulin) produced by the pancreas. How then does this happen?
The hormone leptin has as its primary purpose to protect the body against starvation. It is secreted by adipose (fat) tissue in the body and regularly conducts surveys of the energy or density of energy stored in the adipose (fat) tissues. It works to provide balance between energy intake (from protein, carbohydrates and other nutrients) and energy expenditure (through physical or mental exercise). When this balance is not in place, two different opposites can occur: weight gain can increase or weight loss can be slowed.
Leptin provides these surveys of information to an area of the brain known as the hypothalamus and regulates our being hungry by counteracting the demanded secretion of two feeding stimulants by the hypothalamus and certain gut cells. It also promotes the production of an appetite suppressant. Leptin in normal weight individuals works to maintain proper weight by allowing the brain to believe the body is starved for food. An example of mind over body.
Ghrelin, on the other hand, is a fast acting hormone produced in the gut or intestinal tract which strives to teach the brain that the body needs food. Depending upon the balance of good and bad bacteria in the intestinal tract, ghrelin can become over-produced and confuse the brain about the real need for food. Ghrelin and leptin are in a constant cycle of attempting to be the principle reason we feel hungry or satisfied. Depending on which hormone convinces the brain of the individual’s satiety (not feeling hungry), weight loss may or may not be achieved.
As more adipose (fat) cells are present in the body and the opportunity to produce more leptin exists, why then does the brain not respond to curb our desire to eat more food?
Most overweight individuals have acquired a leptin resistance that actually drives the desire to eat more and more. The individual eats excess food but the brain thinks the body is starving because it cannot get a correct leptin level signal. The result? Weight loss does not occur. But how does leptin resistance occur? There are several stakeholders in this leptin resistance: High stress levels, high fructose corn syrup consumption, eating simple carbohydrates, lack of sleep (a surprising contributor), high insulin levels (major contributor) and even exercising too much. Higher insulin production in overweight individuals adds a confusing signal to the leptin-ghrelin interplay with the brain.
Fixing leptin resistance and allowing weight loss to progress can be encouraged by eating little to no simple starches (potatoes, etc.), highly processed foods (GMO’s), sugars (added un-natural sugars) and fructose. Do not snack! Add more Omega-3’s (fish, grass-fed meats, chia seeds, flax seeds) and minimize intake of Omega-6 consumption (vegetable oils, conventional meats, grains, and gluten) to lower inflammation in the gut and help support balanced leptin and ghrelin levels.
Weight loss is a complex activity. Leptin and ghrelin balance extensively contribute to why individuals cannot achieve successful weight loss and keep the weight off. Weight is the trigger that causes us to believe we are hungry. Weight reduction however, through metabolism adjustment, can ensure the cycle of weight loss and weight gain is interrupted.