Hormones, Exercise and Weight Loss

Someone once said: “I keep trying to  lose weight…. but it keeps finding me!”
Certainly one of the most frustrating  aspects of weight loss is that after you
reach your goal, you often find it  difficult to maintain your new weight  level. This seems to be especially true  for those who are defined as obese.
According to medical research,  approximately 80 percent of obese  people who drop pounds are unable to  sustain their reduced weight. Scientists  believe hormones play a key role in
both weight reduction and weight gain.

Hormones: Loss and Gain

In a study published in the New  England Journal of Medicine, 50
overweight or obese patients underwent  a 10-week low energy weight loss  program. After the diet, they were  found to have an increase in appetite producing  hormones and the levels of
these hunger hormones remained  consistent for a year after the initial  weight loss. This result is believed to  be a main reason why it is difficult for  people to maintain their reduced weight  level, as study participants regained  about 11 pounds (5 kgs) within a year.
One of the most studied hunger  hormones is ghrelin, which is produced  in the stomach and stimulates appetite.
Scientists presented interesting  research at the Endocrine Society’s 92nd  Annual Meeting. In their study, the  researchers administered either a salt  water (placebo) injection or a ghrelin
hormone injection to a small group of  healthy adults – none of whom knew  which type of injection they received.
The study participants were shown  pictures of high calories foods  (chocolate, cake, pizza) and low calorie foods (salads, vegetables, fish). The  participants who received ghrelin
hormone injections were more likely to  rate high calorie foods as appealing  than those who received the placebo  injection.
Another study published by the  Endocrine Society revealed the amount  of appetite hormones present in the  body prior to dieting may be vital to  predicting the likelihood of dieters’
regaining weight. Scientists measured  body weight and appetite hormone  levels on a group of participants before,  during and after dieting. Those study  subjects who had higher plasma levels
of leptin and lower levels of ghrelin  before they started the diet were more  likely to regain weight.3 This knowledge  could be used to develop better  techniques to treat post-diet weight
gain.

However, appetite hormones may have a much wider impact than just promoting or suppressing hunger.
They may actually impact neurological disorders.
Scientists at UT Southwestern conducted investigations that showed the hormone ghrelin may actually
reduce symptoms of stress-induced depression and anxiety. When a person is hungry, his or her body produces
more ghrelin and this could explain why some people eat more when feeling overwhelmed or sad. Scientists used two types of mice in the research.
A test group of mice that were put on a calorie restricted diet displayed lower levels of anxious or depressive behavior
when exposed to stress – such as navigating mazes. Another group of mice also had a calorie restricted diet but they had been genetically engineered not to respond to ghrelin. The genetically altered mice showed higher levels of anxiety and depression when
exposed to stress.

Orexin Spurs Fat Burning

The brain-produced hormone orexin may provide an alternative way to treat obesity. Instead of controlling appetite, orexin appears to help a type of body fat, known as brown fat, to burn
calories. Obese people are often deficient in orexin.
Researchers conducted experiments on mice and discovered a group of overweight mice that were orexin deficient actually ate less than a group of normal weight mice. This leads to the theory the overweight mice were heavier because of inefficient burning
of calories rather than overeating.
While the results are promising, the research has only been conducted on rodents. Human trials would need to happen before any orexin treatments could become available.

A Powerful Ally to Battle Hunger

While some hormones may make losing weight and keeping it off a
challenge, you do have a friend in this hormonal battle: exercise.
A study that appeared in AJP Regulatory Integrative and Comparative Physiology indicates aerobic exercise seems especially beneficial because of its influence over the appetite
hormones ghrelin (promotes hunger) and peptide YY (suppresses hunger).
The test subjects participated in both treadmill running and weight training but at different times. Researchers tested the participants’ levels of appetite hormones and found that after the
aerobic treadmill exercise participants had lower amounts of ghrelin and higher amounts of peptide YY. After the strength training session, the researchers discovered only levels of
ghrelin were affected. Need advice on exercise?

Talk to your chiropractor!