Food and exercise can treat depression as well as a psychologist, according to our study. And it’s cheaper

Around 3.2 million Australians live with depression.

At the same time, few Australians meet recommended dietary or physical activity guidelines. What does one have to do with the other?

Our first test in the world, published this weekshows that improving diet and more physical activity can be as effective as treatment with a psychologist in treating low depression.

Previous studies (incl ours) have found that “lifestyle” treatments are effective for depression. But they have never been directly compared to psychological treatments – until now.

Within a nationwide lack of mental health professionals, our research points to a possible solution. As we found that lifestyle counseling was as effective as psychological treatment, our findings suggest that dietitians and exercise physiologists may one day play a role in the management of depression.

What did our study measure?

During the prolonged COVID restrictions, the anxiety levels of Victorians were high and widespread. Face-to-face mental health services were limited.

Our trial targeted people living in Victoria with elevated anxiety, meaning at least mild depression but not necessarily a diagnosed mental disorder. Typical symptoms included feeling down, hopeless, irritable or tearful.

We teamed up with ours local mental health service to recruit 182 adults and provided group sessions on Zoom. All participants attended up to six sessions over eight weeks, facilitated by health professionals.

Half were randomly assigned to participate in a program co-facilitated by a licensed practicing dietitian and an exercise physiologist. This group – called a lifestyle program – developed eating and exercise goals:

• eating a wide variety of foods
• choosing plant foods with a high fiber content
• including high quality fats
• limiting discretionary foods, such as those high in saturated fat and added sugars
• doing enjoyable physical activity.

The second group took part in psychotherapy sessions convened by two psychologists. The psychotherapy program used cognitive behavioral therapy (CBT), the gold standard for treating depression groups and when delivered remotely.

In both groups, participants could continue existing treatments (such as taking antidepressants). We gave both teams workbooks and obstacles. The lifestyle group received a food hamper, while the psychotherapy group received items such as a coloring book, a stress ball and a head massage.

Lifestyle treatments just as effective

We found similar results in each program.

At the start of the trial we gave each participant a score based on their self-reported mental health. We measured them again at the end of the program.

Over eight weeks, these scores showed reduced symptoms of depression for participants in the lifestyle program (42%) and the psychotherapy program (37%). This difference was not statistically or clinically significant, so we could conclude that both treatments were as good as each other.

There were some differences between the groups. People in the lifestyle program improved their diet, while those in the psychotherapy program felt they had increased social support – that is, how connected they felt to other people – compared to the start of treatment.

Participants in both programs increased their physical activity. While this was expected for those in the lifestyle program, it was less so for those in the psychotherapy program. It could be because they knew they were enrolled in a lifestyle research study and subconsciously changed their activity patterns, or it could be a positive by-product of the psychotherapy.

There was also not much difference in cost. The lifestyle program was slightly cheaper to deliver: A$482 per participant, compared to A$503 for psychotherapy. This is because hourly rates differ between dietitians and exercise physiologists and psychologists.

What does this mean for mental health workforce shortages?

Demand for mental health services is growing in Australia, and so is the workforce faces worsening shortages nationwide.

Psychologists, who provide about half of all mental health services, can have long waiting times. Our results suggest that, with appropriate training and guidance, allied health professionals specializing in nutrition and exercise could help address this gap.

Lifestyle therapies can be combined with psychology sessions for multidisciplinary care. However, diet and exercise treatments could prove particularly effective for those on the waiting list to see psychologists, who may not receive other professional support while they wait.

Many dietitians and exercise physiologists already have advanced skills and expertise in motivating behavior change. Most registered dietitians are trained in management eating disorders or gastrointestinal conditionswhich usually overlap with depression.

There is also a cost argument. It is overall cheaper to train a dietitian ($153,039) than a psychologist ($189,063) – and it takes less time.

Possible obstacles

Australians with chronic conditions (such as diabetes) can access subsidized appointments with a dietitian and exercise physiologist under various Medicare treatment plans. Those with eating disorders can also access subsidized nutritionist appointments. However, mental health care plans for people with depression do not support subsidized sessions with dietitians or exercise physiologists, although top bodies urging them to do so.

Increased training, upskilling, and Medicare subsidies will be needed to support dietitians and exercise physiologists to be involved in the treatment of mental health problems.

Our training and clinic guidelines intended to assist clinicians who practice lifestyle-based mental health care within their scope of practice (activities that a health care provider may undertake).

Future directions

Our trial was conducted during the COVID restrictions and looked at people with at least mild symptoms of depression who did not necessarily have a mental disorder. We seek to replicate these findings and are now running a study open to Australians with mental health conditions such as major depression or bipolar disorder.

If this article has raised issues for you or if you are concerned about someone you know, please call Lifeline on 13 11 14.