In the March edition of Yoga+ Joyful Living, a magazine for yogis, Shannon Sexton, the editor-at-large, explains the importance of sleeping and eating patterns especially during seasonal changes according to Ayurveda, traditional Indian medicine.
Ayurveda, practiced globally, literally means the "science of life" and is still considered an authoritative medicine in South Asia and the Indian subcontinent. In the West it is often referred to as complementary or alternative health practices.
"The body is programmed to direct its energy toward cleansing and assimilation in the hours just before midnight, when agni (digestive fire) is weakest," explains Sexton.
Ayurvedic physicians suggest the following regime, especially during the change of seasons as individuals are connected to the sun's clock according to ayurvedic principles.
Avoid eating late at night (ideally finish by 7pm)
Go to bed at 10pm without television or other stimulants
Agni works in relation to the sun's cycle, and so should your eating patterns:
Rise and eat breakfast around 7am
Lunch should the biggest meal of the day (sun is the strongest)
Dinner the lightest meal of the day (ideally fasting from 7pm to 7am)
This process when followed "supports metabolism, prevents accumulation of ama [toxins] , normalizes weight, and combats kapha imbalances (which are common in the spring)." Kapha is one of three dosha, mind-body constitution, in Ayurveda and the key is to create a balance between mind and body.
Here is more information on dosha, including a checklist to figure out which one represents you: http://doshaquiz.chopra.com/
Yoga+ on the 12-hour fast: http://www.himalayaninstitute.org/yogaplus/article.aspx?id=3591