A new study looks at the effects of exercise on reducing one’s appetite.
There are several hormones that help regulate appetite, but the in a study attention was payed to ghrelin and peptide YY. Ghrelin is the only hormone known to stimulate appetite whereas, peptide YY suppresses appetite.
In the study, eleven male students did three eight-hour sessions. During one session they ran for 60 minutes on a treadmill, and then rested for seven hours. During another session they did 90 minutes of weight lifting, and then rested for six hours and 30 minutes. During another session, the participants did not exercise at all.
The participants filled out surveys indicating how hungry they felt. The researchers measured ghrelin and peptide YY levels at multiple points along the way.
It was found that the treadmill activity caused ghrelin levels to drop and peptide YY levels to increase. However, weight-lifting produced a mixed result. Ghrelin levels dropped, yet peptide YY levels did not change significantly.
Both aerobic and resistance exercise suppressed hunger, but aerobic exercise (treadmill) produced a greater suppression of hunger. The changes the researchers observed were short term for both types of exercise and only lasted for 2 hours.
While the study showed that exercise suppresses appetite hormones, the next step is to establish whether this change actually causes the suppression of eating.
I personally think that 60 minutes on a treadmill or 90 minutes of weight lifting is a bit excessive. I don’t think there is too much benefit in straining your body for that long unless you are an athlete and are competitive. Even so, the study shows that working out has a dual effect on losing weight: exercise burns calories and also causes you to be less hungry.
Adapted from materials provided by the American Physiological Society.