Exercise may be one key to preventing overeating.  

Exercise couple

With the ever-growing obesity epidemic, it is essential that we slow the growth of the world’s waistline.  The “exercise more and eat less” crowd has long touted this mantra as the solution for overeating and weight gain.  The group points to sell control and an inability to maintain good control of food intake as the cause of the epidemic.  No matter whether the cause of obesity is overeating, it is essential that we curb the currently growing rate of obesity.  Although I would argue that a six-pack of abdominals and weight loss occurs more in the kitchen than in the gym, exercise may have some benefit in reducing your appetite.  

A new article from 2017 published in Clinical and Research in Arteriosclerosis looked at this very question[1].   The main purpose of the article was to review the evidence on the influence of physical exercise has on appetite through changes in hormone concentrations and changes in certain neuronal regions in the brain.  The results of the reviewed research appear to show how exercise produces changes in appetite perception, the amount of energy intake, and indifferent weight-control-related hormones.  The researchers concluded that exercise leads to positive changes in appetite, hunger, and energy intake and leads to decreases the ghrelin (hunger hormone) levels and increased concentrations of leptin (satiety hormone).  If true, the exercise would be beneficial for weight loss by reducing your hunger and cravings.  

I decided to research the claims of this article and below is a list of what I found:  

1. Appetite: Exercise appears to lower your appetite.  This result has been confirmed by multiple studies[2],[3],[4],[5].  In particular, the effect of appetite suppression appears to increase with the intensity of the exercise[6].  The combination of the diet and exercise appears to also have a beneficial effect on appetite and adipokines dysregulation[7].
2. Leptin: Leptin is the satiety hormone.  Help levels of leptin are associated with lower hunger or increased satiety.  It signals the body to feel full.  Research has proven that exercise increases leptin[8],[9].  
3. Ghrelin: Ghrelin is the hunger hormone.  High levels of activated ghrelin are associated with increased hunger.  The results differ in many studies.  Some show ghrelin is decreased and others show that is inactivated by being acylated[10].  Both have the same effect so exercise suppresses hunger by suppressing ghrelin activity.  
4. Peptide YY (PYY): PYY is another hormone or peptide (amino acid chain) associated with suppressing hunger.  Higher concentrations in blood plasma are associated with aerobic exercise and lower levels of hunger[11].  

The bottom line: Although exercise is unlikely to create lasting weight loss on its own, in most instances, exercise decreases appetite through hunger and satiety hormones and will help you lose weight.  Exercise has long been touted as the cure for obesity and they might not be 100% correct but it definitely appears to be tied to increase satiety and decreased carvings.