In the past couple of weeks we’ve covered the topic of cortisol as well as ghrelin and leptin. In addition to these, our weight and appetite regulation system includes a long list of hormones, neurotransmitters, and other substances that act as checks and balances to ensure that our body consumes, stores, and burns an appropriate amount of energy. Although the list below covers many of the other major players, a complete understanding of this system may require the purchase of a textbook.
Insulin and Glucagon: The Blood Sugar Hormones
Insulin and glucagon primarily act to regulate blood sugar – insulin reduces blood sugar levels, glucagon increases blood sugar by breaking down glycogen from the liver. Insulin, however, also has important roles in fat storage. Long story short, if insulin is present more often and in greater amounts than it should be, the likelihood of weight gain increases. Food choices rich in protein and fiber-rich carbohydrates (think fruits, vegetables, and whole grains) will help reduce your body’s reliance on insulin to lower blood sugar levels and store excess energy.
Estrogen and Testosterone: The Sex Hormones
Each of these promotes the burning of fat for energy. Unfortunately, both estrogen and testosterone levels decline with aging, leading to a reduced metabolic rate, increased visceral (belly) fat, and muscle loss. Fortunately, we can work against this process with good nutrition and strength-building activities.
CCK and PYY: The Other Fullness Hormones
We’ve previously discussed leptin as a fullness hormone, but cholecystokinin (CCK) and peptide YY (PYY) are also satiety hormones. Each of these is produced in the intestines in response to digestion.
Dopamine and Food Cravings
Although food addiction remains a hotly debated topic, we all have food cravings. Dopamine is the main reason why. While dopamine isn’t technically a hormone (it’s a neurotransmitter), it is triggered by hunger hormones like ghrelin. Dopamine’s release in the brain’s pleasure or reward centers is the primary mechanism for food cravings. In another example of “why diets don’t work”, leaving yourself hungry triggers the ghrelin-dopamine connection, leading to thoughts about all the foods you aren’t allowing yourself to have.
Human Growth Hormone
Human growth hormone, or HGH, is secreted by the pituitary gland in the brain and helps to increase metabolic rate, burn fat, and build muscle. Much like testosterone and estrogen, HGH production declines with aging. Sleep is the key behavior to boost human growth hormone as its production peaks during periods of deep sleep. Before you go looking for HGH supplements online, however, please know that oral HGH supplements are ineffective as they are digested in the stomach, and injectable HGH is only approved for specific medical purposes – as well as having a long list of potential side effects.