By understanding how hormones such as insulin, thyroid, serotonin, leptin, and cortisol work, we can regulate our weight more effectively.

Like many readers of alive, one of your New Year’s resolutions may have been to lose a few pounds. If you’ve already eaten your way through January, you’re not alone. Long-term studies show that one to two-thirds of weight lost through dieting is regained within one year. Almost all weight is regained within five years - disheartening information if you’re trying to lose weight by restricting calories.

Yet we know that packing around too many pounds can lead to cardiovascular disease, type II diabetes, cancer, osteoarthritis, sleep apnea, gastric reflux, and many other health complications. Most people lose weight to fit into a smaller clothing size, but being fat takes years off our lives and the emotional, physical, and societal costs are exorbitant.

I spent most of 2003 writing a book on fat loss. While wading through references, I was excited by research showing that not only the food we eat but certain hormones, including insulin, thyroid, serotonin, leptin, and cortisol, determine whether we are skinny or fat. By understanding how these hormones work we can regulate our waist size more effectively.

Sour Side of Insulin

High levels of insulin may contribute to our fatness. Insulin, the blood sugar regulator, is pumped out in excessive amounts as it tries to reduce the abnormally high blood sugar that results from a high carbohydrate, low protein diet. We inevitably gain weight and become fat, and our cells become resistant to insulin and fat loss.

Cortisol

High insulin also increases the secretion of cortisol, our stress hormone. High cortisol causes a corresponding drop in the hormone dehydroepiandrosterone (DHEA), which, among other actions, helps to increase muscle mass. More muscle mass is needed for fat loss, as it increases fat burning and reduce insulin.

Chronic stress also activates all fat cells to store fat. The central fat cells, found mainly deep in the abdominal wall, have four times the cortisol receptors on their cell membranes. Each time we are stressed the cortisol-fat mechanism turns on and our body stores more fat.

Body Fat and Leptin

Another hormone - leptin, produced by body fat - is critical in telling the body when to eat and when we are satisfied. Scientists have learned that in some people the message of satiety is not heard and fat cells send out more and more leptin, causing resistance to leptin, increased food cravings, and the desire to continue eating. In other people, leptin levels are low due to zinc deficiency.

Serotonin Satisfaction

The hormone serotonin, a neurotransmitter in the brain made from the amino acids found in proteins, is also involved in signalling satisfaction. Low serotonin levels cause depression, obesity, lethargy, a preference for refined carbohydrates, and overeating because the brain senses it is starving. A diet that restricts protein-rich calories causes serotonin levels to plummet. People who are hyper-secretors of cortisol also exhibit suppressed serotonin levels.

Thyroid to Go

Low thyroid - called hypothyroidism - affects approximately 30 percent of the population in Canada. Low thyroid reduces our fat burning rate and causes fatigue, inhibiting energy levels.

Scientists have unlocked the secret to fighting fat. Diets don’t work. We must eat to ensure healthy hormones, eat less, walk, and laugh more.

Lorna Vanderhaeghe, MS, is the author of several books, including the best seller Healthy Immunity: Scientifically Proven Natural Conditions from A-Z (Wiley and Sons, 2001) and No More HRT: Menopause Treat the Cause (Fitzhenry and Whiteside, 2002). She is also senior editor of Encyclopedia of Natural Healing (alive Books, 2002). Look for her Web site at healthyimmunity.com.