Low moods, sweet cravings, increased appetite, fatigue and increased need for sleep occurring for some during the fall/winter months is a phenomena termed Seasonality. These symptoms which are similar to seasonal changes in behaviour shown by many mammals in response to winter, might be a human expression of a basic evolutionary process to achieve maximum conservation of energy during winter. This is however not a universally experienced condition-almost as if some of us have evolved better than others in this respect.
Research shows Vitamin D and Serotonin to be at the forefront of these changes with both being greatly affected by natural light. Due to the decrease in the intensity and duration of sunlight and hence our overall bodily exposure to light of the full-spectrum, levels of both hormones may be reduced to below optimal levels in susceptible individuals (due to genetics, environmental factors and nutritional balance).
There are many ways in which one could naturally increase both hormones to optimal levels. Due to the unique way in which Seasonality affects people, its treatment also requires an individual approach.
If you find you suffer from the above-mentioned symptoms during 
the fall and winter months, you may consider seeing a health-care practitioner who could help you gain a better understanding of how you can best deal with these changes.
