Up to half a million people in the UK are estimated to be affected by Seasonal Affective Disorder (SAD) every winter between September and April. SAD from lower sunlight levels can cause many different symptoms from oversleeping, depression, joint pain, lowered immunity to infections, loss of libido to unwanted weight gain.

A harvest festival of healthy foods could be the answer to the carbohydrate cravings we often experience during the longer hours of winter darkness. The human body produces hormones to control our waking and falling asleep that should follow the natural amounts of daylight. The pineal gland in the brain governs the production of nocturnal melatonin to make us drowsy in darkness and is sensitive to signals of light from the eyes to make serotonin to wake us refreshed.

If you've spent the spring and summer on a weight loss diet, you could well be low in tryptophan which we need to convert to serotonin, the 'happy mood' neurotransmitter, vital to our brains. Low levels can cause depression, serotonin also controls your appetite – the more you make - the less you want to eat, which is why many depressed people feel the need to comfort eat. Significantly, lower daylight levels in autumn and winter cause us to make less serotonin, hence our bodies are set on storage mode.

Try supplementing 150mg 5-hydroxytryptophan (5-HTP) (Serotone £18.50 for 90 50mg tablets from Higher Nature www.highernature.co.uk 01435 884668), made from tryptophan, together with a B-vitamin complex and zinc, for a fast reduction in appetite with less cravings for sugar and carbohydrate. Turkey is high in tryptophan which may explain turkey's popularity at Thanksgiving and Christmas.

When your blood sugar levels rise, you produce the hormone insulin to help transport sugar from blood into your cells. Excess sugar turns to fat, but the more frequently blood sugar rises because of constant snacking or grazing on sugary snacks and carbohydrate foods, the more insulin you produce. Too much insulin will turn blood sugar into body fat so the smallest indulgence can mean more weight gain. Cells stop responding to insulin over time resulting in diabetes.

You do need some carbohydrate when you eat protein foods because the tryptophan in proteins has to compete with other amino acids to get into your brain. The hormone that helps drive tryptophan is - guess what? - insulin, made from eating carbohydrate.

The carbohydrates to choose that won't rocket your blood sugar are the complex slow-releasing variety found in fresh vegetables, lentils and beans, and whole grains like brown rice, millet and buckwheat. So put together fish with brown rice, tofu with vegetables, meat with wholegrain pasta.

Foods like wholewheat flour, bread and pasta, mushrooms, asparagus, beans, nuts and seeds are rich in chromium which not only aids insulin but also makes glucose tolerance factor to get sugar into cells.

Make sure you eat (or take a supplement) enough omega-3 fats from oily fish 2-3 times a week or linseeds (flaxseeds), 1 tablespoon a day ground in a coffee grinder and sprinkled on fruit or cereal. Omega-3 fats are used by the brain, skin, immune, hormone and cardiovascular systems, and promote weight loss by counteracting insulin resistance.

Choose low glycemic index fruits such as apples, pears and autumn berries with a small handful of fresh nuts to eat as snacks between meals. Your blood sugar will stay nice and even.

Autumn brings a plethora of wonderful nutrient-rich foods to the table to boost your immunity for the winter months ahead. Keep your summer glow with vitamin C rich oranges and lemons. Look for chestnuts to roast and make delicious chestnut soup. Pumpkins and butternut squash make wonderful pies and soups. Make smoothies from apples, pears and wild blackberries and freeze the surplus. Drink 6-8 glasses of fresh filtered or bottled water to clear toxins.

Exercise as much as possible in the outdoors throughout the winter, even on the coldest, most dismal day you can get the benefits of daylight on your face and fresh air can benefit circulation. Enjoy a brisk walk on the sunnier days and you should feel the benefit.

© Lynn Alford-Burow September 2007