The reality of life is this; STRESS HAPPENS. If It does not occur in your life, you’re not human. It is a current of waves that bombard’s one and may alter one’s moods, relationships and, most importantly, habits. If a significant amount of stress plagues your life it will lead to many issues either short term or long term; blood pressure, diabetes, migraines, and unwanted weight gain, to name a few.
Stress occurs due to both psychological and hormonal responses to certain situations, work loads and the feeling of doubt. It's because of these factors it's imperative to balance these moods with proper exercise and dietary habits that will "balance out" cortisol (the stress hormone), and prevent weight gain and other potential health-related issues.
Cortisone is released by the body in times of stress to stimulate fat, insulin and blood sugar levels, which essentially provides energy. This will result in an increase in appetite. At this state, one may eat a significant amount of calories, or in some cases, store glycogen and fat to prevent weight loss.
Balancing Stress with relievers (the right kinds) are KEY. Alcohol is a no-no. countless articles (which I won't go into detail here) will say alcohol will do more harm than good. Same thing with drugs. What I'm promoting is the balance of proper eating, resting and exercise activity that will combat the inevitable exposure to stress, and to do it daily.
Exercise is likely the LAST thing on your mind when you're dealing with life's stresses. This I am aware. On the other hand the studies are out there: working out on a consistent basis may limit or completely eliminate the symptoms of stress and depression.
If you're experiencing health problems (i.e. high blood pressure, diabetic, or even clinically diagnosed bi polar disorder) its highly recommended by health care practitioners or doctors to get involved in a structured exercise regimen to battle the psychological effects.