It’s the season of mists, mellow fruitfulness — and comfort food. But try to resist — or, at least, don’t go for the traditional, stodgy, fat-laden offerings. Research published last week in the British Journal of Psychiatry (BJP) showed that people who ate a Mediterranean-style diet (fruit, vegetables, pulses, cereals and olive oil) were 30 per cent less likely to get depressed than those whose diet was laden with processed and high-fat foods. And since the No 1 rule for keeping your mood on an even keel is to eat regularly during the day, you can take comfort from the fact that the research doesn’t advocate starving yourself.

Just the simple task of eating the right breakfast after a night’s fast will boost not only mood, but also memory, learning power and concentration, probably by increasing production of the nerve transmitter acetylcholine. The key is to stay off fast-release carbohydrates such as croissants with jam, cereal bars, muffins, sugary cereals and sweet drinks. These are digested rapidly, giving your blood glucose an exaggerated spike, which is swiftly followed by a low.

Instead, opt for slow-release glucose found in foods such as sugar-free muesli with berries, porridge or sourdough toast with peanut butter — choices that are more likely to keep moods level by delivering a stable and steady flow of energy to the brain and by keeping you feeling full for the morning ahead.

At lunchtime, concentrate more on protein. This seems to make us feel more mentally alert, and serotonin, the neurotransmitter in our brains that makes us feel happy, is made from tryptophan, an amino acid found in protein-rich foods such as fish and meat. Try a good-sized serving of lean chicken, turkey, fish or pulses with salad or vegetables, rather than your usual sandwich, to avoid that afternoon slump. Fish is particularly good since it contains gamma amino-butyric acid (GABA), which provides mood-elevating effects by blocking anxiety and stress (mackerel has particularly high levels). Sprinkle toasted sesame seeds on your salad and you’ll put an extra spring in your step; these are one of the best sources of the essential amino acid threonine, low levels of which are associated with depression.

Snack on them too, when the inevitable mid-afternoon dip occurs. Try also to have plenty of beautiful, colourful fruits around — a bowl of satsumas on your desk, perhaps. Psychologists believe that merely looking at the bright reds, oranges and yellows of apples, strawberries and bananas can make us feel happier.

Dr Tasnime Akbaraly, co-author of the BJP report, says that “consuming fruits (along with vegetables and fish) may afford protection against the onset of depressive symptoms” and cites previous studies which suggest that high levels of antioxidants, present in fruit and vegetables, could also protect against depression. Nuts make an ideal snack; as well as being a good source of B-vitamins and protein, they are rich in selenium, a mineral with moodenhancing qualities. Brazil nuts are the best source.

Of course, chocolate is the one snack that everyone knows instinctively will give them a lift. Chocolate, especially the dark, good-quality variety, contains high quantities of phenols, antioxidants that boost mood, and N-acylethanoloamine chemicals, which stimulate the brain to release endorphins. But chocolate is fattening, so the key is to have a piece or two, not a whole bar.

To remain upbeat, even at the end of the day, an evening meal rich in carboyhdrates is best (despite the current “no carbs after 5pm” orthodoxy). It will also help you to sleep better, which in itself improves mood. When your body processes carbs, blood-sugar levels rise, prompting the pancreas to release more insulin into the bloodstream, which helps tryptophan to reach the brain more easily. According to a study from the Massachusetts Institute of Technology, eating carbohydrates with little or no protein stimulates serotonin production, so try pasta with tomato sauce, a stir-fry with rice, or a baked potato (or sweet potato, which is higher in fibre and better at regulating blood sugar levels).

Finally, maintaining hydration is crucial to ensure an even mood. Even small decreases in hydration levels can leave you feeling grumpy. Keep water or caffeine-free drinks to hand and top up fluids regularly, especially when sitting in heated rooms, dreaming of the sunshine.

Best happy foods

Bananas are an excellent source of starchy carbohydrate, which encourages production of the “happy hormone” serotonin.

Green vegetables — broccoli, cabbage and spinach — contain folate, a natural protection against depression.

Nuts and seeds: a great source of magnesium, which helps the body to make serotonin more effectively.

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