The transition from summer to autumn and into winter can be tough for a lot of us. Once you get through the confusion of September's in-between weather, you're faced with chillier temperatures and darker days ahead. As much as we're enjoying the return of The Celebrity Traitors and looking forward to bringing out our best knitwear, entering October can feel daunting.

Will the lack of light cause seasonal affective disorder to hit? Will our energy levels grind to a complete halt once temperatures cool? Will we lose all motivation to leave the house (and our multiple layers of blankets)?

These are big worries. So any and all hacks we come across that could potentially make us feel better are eagerly snatched up.

One such hack? Making a change to your diet in the autumn/winter months (and year-round, really). That change is ditching ultra-processed foods.

Don't panic – we're not for one moment suggesting abandoning all carbs or baked goods. Those are autumnal essentials in our books. But the comfort foods that have ingredients lists the length of your forearm might be worth cutting back on.

collage of variety of highly processed food
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This is due to a new study from UC San Francisco, which suggests that eating fewer ultra-processed foods may help to reduce symptoms of depression. It's a small study, involving just 20 people, but it adds to growing evidence that suggests prioritising natural whole foods can be beneficial for our mood.

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The research saw the participants, who had an average age of 44 and the majority of whom were women, divided into two groups: one that stuck with their usual diet for four weeks, while the other switched to a diet low in ultra-processed foods such as packaged treats loaded with preservatives and fast food items. The participants in both groups were able to choose what they ate with guidance from the research team.

The participants who dramatically cut down their intake of ultra-processed foods showed moderate to large improvements across three different measures of depression, and anxiety scores improved, too. Researchers believe this is down to how ultra-processed foods may impact gut health, and noted that while it can be difficult to cut out ultra-processed foods entirely, reducing your intake could be well worth the effort.

One of the study's authors, Nyasha Chagwedera, said: 'Reducing the amount of ultra-processed food in our diet can be challenging, because it's highly palatable, cheap, and convenient. Ultra-processed food triggers dopamine, the pleasure hormone, which promotes craving. Food companies work with scientists to find just the right amount of sugar, salt, and fat that make you want to eat more and more.'

Chagwedera described ultra-processed foots causing 'gut damage [that] can create low-grade, chronic inflammation throughout the body that either directly causes depression or makes people more vulnerable to it.'

This is far from the first time links have been found between gut health and mental wellbeing. Previous research has suggested that inflammation of the gut can trigger depression and anxiety, while consuming adequate levels of nutrients such as polyphenols and omega-3 fatty acids is linked to improved mood.

Of course, it's important to note that seasonal affective disorder, depression, and anxiety are all serious mental health conditions that require proper, medical treatment. If you are struggling with any symptoms related to these issues, it's incredibly important to speak to a medical professional about potential routes for treatment, which may include medications such as SSRIs and talking therapies. Simply switching up your diet is not an instant fix to mental illness.

But in combination with treatment, or to potentially provide small uplifts in how you're feeling day-to-day, it may well be worth reducing the amount of ultra-processed foods you're eating, and instead loading up on foods that have been linked to mental wellbeing – such as oily fish, leafy greens, whole grains, and nuts and seeds.