"As the days get shorter my mood changes substantially and I start to feel the symptoms of SAD. How can I manage the effects of a change in season through my diet and lifestyle?"

JS, Surrey

If you find it hard to get out of bed on these dark mornings, you feel low, even depressed, and you have a sudden urge to raid the biscuit tin or get stuck into some real comfort food then you may be suffering from Seasonal Affective Disorder (SAD). During the winter months the lack of daylight hours combined with what we eat may lead to a reduction in a brain chemical called serotonin. Low levels of this important brain chemical influences our mood leaving us depressed, lethargic and in some cases even disturbing our sleep.  Interestingly, more women than men experience these symptoms and it can be particularly noticeable leading up to a menstrual period. You should aim to incorporate some of these modifications to your diet and lifestyle to help alleviate your symptoms.

Be sure to make the most of any dry and bright days during the Autumn and Winter months, getting out in the open air for a brisk walk, even for just 10 minutes, can help lift moods. There is no substitute for natural light and exercise, both of which help improve sleep patterns, appetite and mood.

Make sure your diet includes foods rich in the amino acid, tryptophan, which is the precursor of serotonin. Useful options include chicken, turkey, soya, low fat dairy including cottage cheese, nuts, seeds and bananas. Chocolate is a very useful source of tryptophan and a great mood lifter, choose 70% cocoa chocolate to help stabilise blood sugar levels. Ideally start the day with a bowl of cereal and milk, such as Lizzi's Belgian Chocolate Granola;

Eat little and often during the day and never skip meals, ideal snacks include oat cakes with nut butter;

- Avoid an alcoholic night cap and instead go to bed with a milky drink and an oatcake or oat biscuit.
  
- Vitamin D is particularly useful for the symptoms of SAD so be sure to include oily fish, egg yolks and fortified cereals in your diet. 
      
- Light therapy may help normalise the impact of reduced daylight by lengthening the photoperiod you are exposed to. Many people find dawn simulation using a "body clock" works well or you can choose from one of the many light boxes, clocks or desk-lamps that are now widely available.  However, avoid the use of a light box after 7pm or you may disrupt your sleep.