Research into eating disorders
Seasonal variations in eating disorder subtypes in
Int J Eat Disord. 2003 Jan;33(1):71-7
The seasonality of Bulimia Nervosa in Kyoto is the highest among eating disorder subtypes, although lower than that in North America. This finding suggests that light therapy could be useful for Japanese BN patients.
This Japanese research found that 40% of their sample suffered from SAD. This finding led the researchers to suggest that if SAD symptoms could be alleviated by using light therapy then people with Bulimia Nervosa may also be helped by using light therapy as it may reduce over-eating and food cravings. Other researchers have noted that a large number of people suffering from Bulimia Nervosa seem to be improved in spring and relapse in winter.
The relationship of affective state to dietary preference: winter depression and light therapy as a model
J Affect Disord. 1990 Sept;20(1):43-53
Examined the feeding habits of 39 SAD patients (aged 16-69 years) to determine whether they crave carbohydrates when depressed during winter. Dietary intake was measured using a daily food/drink frequency questionnaire over 4 conditions: when depressed in winter, during light therapy, during withdrawal, and when euthymic in summer. Carbohydrate intake (both sweet and starch) in the 2nd half of the day was elevated during winter depression and was as low after light therapy as in summer.
Many people with SAD tend to over-eat or experience food cravings.
Light therapy for seasonal Bulimia
American Journal of Psychiatry. 1989 Dec;146(12:1640-1
Reports the case of a 21 year old woman with seasonal bulimia who was treated with light energy. She was exposed to 2500lux light from 6am to 8am for 2 weeks during the winter. She improved in mood ratings and weekly binge/purge episodes during treatment with bright as opposed to dim light. Explanations are offered in terms of SAD and neuropsychological dysfunction.