Much research has been done on the effects of cortisol. Researchers have shown that cortisol levels and plasma levels of the appetite-controlling hormone leptin are related to each other in a negative and positive environments. In other words, when cortisol decreases, leptin decreases and when cortisol rises, leptin rises. In addition, stress is the most commonly reported trigger of binge eating, and high cortisol levels correspond to both central body fat and food intake after stress. After stress, increased cortisol levels have been associated with increased food intake and no doubt associated to the serum leptin levels. 

In an other study researchers discovered that excess cortisol impacted greatly on what is referred to as insulin resistance; the inability of the cells to up take glucose due to the an over responsive reaction to insulin. The researcher stated, “Since cortisol promotes the development of visceral obesity, and has a direct negative impact on insulin function throughout the body, even a modest sustained up-regulation of cortisol production may have the potential to increase risk for insulin resistance syndrome and type 2 diabetes.” 

Cortisol Control and Weight Loss

Several natural compounds have acted as cortisol-controlling substances. a extract from Magnolia officinalis bark and an extract from Phellodendron amurense bark. In a clinical trial, 49 stressed subjects, who suffered from stress induced overeating, were given two to three doses per day of Magnolia officinalis extract for two weeks. After consumption, there was a 76 percent decline in high fat/sugar/salt snack eating.

In another study, 50 stressed people were given 200 mg Magnolia officinalis extract three times daily for two weeks. Post-trial analysis revealed that 82 percent found the Magnolia officinalis extract effective in controlling stress-induced symptoms, such as depression, anxiety, irritability, emotional ups and downs, concentration difficulties and restlessness. Seventy-eight percent reported increased relaxation, while 74 percent had more restful sleep. No significant side effects were reported, although 24 percent reported some temporary initial drowsiness, and 6 percent reported mild and transient stomach upset.

Withania is another cortisol-lowering substance, is extract of roots and leaves from Withania somnifera, also known as Ashwagandha. Withania somnifera has been shown in a number of animal studies to reduce the effects of stress, indicating it may help people who are prone to stress related eating or whose excess pounds are due to unbalanced cortisol levels. Withania can be standardized to contain the proper amounts of glycowithanolides, Withaferin -A and oligosaccharides’ that research has shown to promote optimal anti-stress activity.

Cortisol and Insulin Resistance

The ability of elevated cortisol to promote insulin resistance may explain why high cortisol is linked to weight gain and how stress is one of the precursors to this modern day problem.

In one study of six normal volunteers, researchers administered cortisol infusions into the subjects, which increased the plasma cortisol concentration approximately four fold to values observed during moderately severe stress. These high cortisol levels increased plasma glucose and plasma insulin concentrations. The high cortisol also increased rates of glucose production and the rate at which the body used the glucose.

The Brown University Medical Student Study further illustrated the relationship between cortisol and insulin. The researchers examined students during a baseline control period as well as during two examination periods. During these timeframes, the researchers noted weight changes in self-proclaimed stress eaters compared to non-stress eaters. Stress eaters tended to gain more weight and demonstrated increases in nocturnal levels of insulin, cortisol and blood levels of total / HDL cholesterol ratio during exam periods compared to the baseline control period.

Insulin Involvement

High insulin is the enemy of dieters because insulin is critical for glucose metabolism, storage and maintenance, wasn’t meant to occur in excessive levels. When food is consumed, the digestive process converts carbohydrates into glucose, a simple sugar, which is absorbed into the blood stream. The pancreas releases insulin in response to blood glucose. Insulin then enters certain cells and triggers events that cause the cells to absorb glucose from the blood.

The consumption of excessive amounts of refined carbohydrates and sugar, however, can result in insulin resistance, the gradual loss of sensitivity to insulin by many tissue cells. The body responds by producing even more insulin, which results in high levels of insulin, glucose and other unabsorbed nutrients circulating in the blood stream. Because of cortisol’s ability to elevate insulin levels, when normalizing cortisol levels to achieve weight loss it is also helpful to stabilize blood sugar.