Overweight and obesity are taking over our country. One factor frequently overlooked in this growing epidemic is the role of hormones. Instead we focus on food and exercise which are certainly important, but for many individuals struggling with their weight nutritional and exercise approaches are not enough. Without optimal hormone levels it is difficult to achieve weight loss.
How Hormones Regulate Weight
There are 3 basic mechanisms by which hormones regulate weight and body composition.
- Stimulate metabolism.
- Stimulate muscle growth and fat loss.
- Control appetite.
A big problem as we age is the slowing of metabolism. Loss of muscle is one factor that affects metabolism, and one reason we encourage our patients and readers to engage in a resistance/strength training program.
Thyroid is the main hormone that directly affects metabolism. There are different types of thyroid hormones which causes some confusion and misunderstanding. T3 is the main hormone that stimulates metabolism. It is derived from T4. T4 is the main hormone produced in the thyroid gland. It really is a prohormone. When things are working well T4 gets converted to T3 in the cell. T3 is 4 to 5 times more potent than T4, but the thyroid gland produces 4 to 5 times more T4 than T3.
It’s been practice by most physicians to prescribe T4 with the thought that the body will convert it to T3. The problem is the conversion from T4 to T3 is affected by age, underlying disease, and medications. We typically prescribe a combination of T3 and T4 in our patients with low thyroid in a 4 to 1 ratio of T4 to T3 mimicking the body’s production.
Adrenaline is another hormone that speeds metabolism. Adrenaline is released during flight of fight responses. It’s the hormone of emergency providing us with a rapid source of energy through the burning of fat and sugars to survive physical threats.
Glucagon has the opposite effects of insulin, but doesn’t get nearly the attention that insulin gets. Insulin converts calories into fat and glucagon stimulates the release of calories from fat. Glucagon release is stimulated by blood sugar level that’s too low, in response to protein consumption, and during exercise. But don’t get carried away with eating too much protein. The goal is to keep blood sugar levels normal while maintaining muscle mass. The best way to do this is to eat protein along with low glycemic foods.
Hormones that Build Muscle and Burn Fat
DHEA, testosterone, and growth hormone are the main muscle-building and fat burning hormones. We’ve discussed all 3 in previous articles.
DHEA is a precursor hormone to our sex hormones; testosterone, estrogen, and progesterone. It has one-twentieth the potency of testosterone. DHEA counteracts many of the effects of cortisol, the stress hormone. DHEA builds muscle, increases the burning of fat, improves libido, builds bones, and improves our ability to cope with stress.
Testosterone is known for being the muscle-building hormone. By maintaing lean body mass, testosterone preserves metabolism. It also inhibits an enzyme called LPL (lipoprotein lipase). Inhibiting LPL frees fatty acids from our fat stores enabling them to be burned for energy. Testosterone levels decline with age, chronic disease, obesity, and from exposure to toxins in the environment. Testosterone levels are declining globally, and that decline is most likely related to environmental issues. Read our many article on this all important hormone. The main point is testosterone is a total body hormone.
Testosterone is not just for men, either. Women can benefit from it, too.
Growth hormone is released during sleep and is the main regenerative hormone of the body. It repairs tissues and builds muscle and bones. Most of the actions of growth hormone are carried out by IGF-1 which is more easily measured in the blood than growth hormone itself which has a short half-life. The fact that growth hormone is released during sleep (but also following intense exercise) highlights the importance of getting plenty of restful sleep. Growth hormone has consistently been shown to improve lean body mass while facilitating the burning of fat.
Weight loss (loss of fat) is easier when these hormones are at optimal levels.
Hormones that Control Appetite to Achieve Weight Loss
Several hormones affect appetite and include melatonin, serotonin, dopamine, acetylcholine, leptin, vitamin D3, GABA, and ghrelin.
We will save a discussion of these hormones for a future article, “Hormones That Control Appetite and Weight”.
See related articles.