Is your diet secretly harming your mental health? New study answers!
We all know the feeling: you start a new diet with the best of intentions, determined to shed a few kilos, boost your energy, or simply feel a bit healthier.
But what if, in your quest for better health, you’re actually putting your mental wellbeing at risk?
A new study has sounded the alarm, suggesting that taking calorie restriction too far could have serious consequences for your mood and mental health, especially for men and those already carrying a few extra kilos.
The surprising link between strict diets and depression
Published in the journal BMJ Nutrition, Prevention & Health, this large-scale study analysed data from over 28,000 adults, examining their eating habits and symptoms of depression.
The findings? People who followed calorie-restrictive diets—particularly men and those with a higher body mass index (BMI)—were more likely to report symptoms of depression.
But it’s not just about how much you eat. The quality of your diet matters, too. Those who filled their plates with ultra-processed foods, refined carbs, saturated fats, processed meats, and sweets were more likely to feel down in the dumps.
On the flip side, people who embraced a Mediterranean-style diet—think plenty of veggies, whole grains, olive oil, and lean proteins—generally reported a lower risk of depression.
Dr Venkat Bhat, the study’s lead author and a psychiatrist at St. Michael’s Hospital and University of Toronto, puts it simply: ‘The findings suggest caution with overly restrictive or unbalanced diets, particularly for people already experiencing weight-related stress or challenges.’
In other words, balance is key—not just for your waistline, but for your mind as well.
Why do extreme diets affect our mood?
It’s tempting to think that eating less will always make us feel better, especially if it leads to weight loss. But the reality is more complicated.
Previous research has shown that supervised, medically-guided calorie restriction can actually improve mood in people who are overweight or obese—likely due to physiological changes, improved mobility, and positive social feedback.
However, when people embark on unsupervised, extreme diets—often cutting out entire food groups or slashing calories to unsustainable levels—the results can backfire.
Without proper nutrition, your body may not get the vitamins, minerals, and energy it needs to function. This can lead to fatigue, sleep problems, difficulty concentrating, and, yes, a dip in your mood.
There’s also the emotional toll of ‘weight cycling’—the familiar pattern of losing weight, regaining it, and starting all over again.
This yo-yo effect can be disheartening and may actually increase symptoms of depression and anxiety.
And let’s not forget: extreme dieting is a known risk factor for developing eating disorders, which can have lifelong impacts on both physical and mental health.
The importance of balance and professional guidance
So, what’s the solution? According to the experts, it’s all about finding a sustainable, balanced approach to eating.
Dr Johanna Keeler, a postdoctoral researcher at King’s College London, points out that previous studies showing benefits from calorie restriction involved diets supervised by medical professionals.
‘Unsupervised dieting, which can produce nutritional deficiencies, might not be good for depressive symptoms,’ she warns.
Dietitian Natalie Mokari suggests starting with small, manageable changes. Instead of focusing on what you can’t eat, try to build meals that include a balance of protein, carbohydrates, healthy fats, and plenty of fibre from fruits and veggies.
Slow down at mealtimes, listen to your body’s hunger cues, and don’t be afraid to seek help from a registered dietitian or your GP.
Dr Kary Woodruff, a nutrition expert at the University of Utah, sums it up: ‘Regardless of weight loss, improving dietary quality can significantly improve overall health and quality of life.’
What does this mean for older Australians?
As we get older, our bodies—and our minds—change. Many of us become more conscious of our health, and it’s common to want to lose a bit of weight or eat better.
But it’s important to remember that drastic changes aren’t always better. In fact, they can sometimes do more harm than good.
If you’re considering a new diet, especially one that involves cutting calories or eliminating certain foods, have a chat with your doctor or a qualified dietitian first. They can help you find an approach that supports both your physical and mental wellbeing.
Your turn: Have you tried a restrictive diet?
We’d love to hear from you! Have you ever tried a strict diet, and did it affect your mood or mental health? What strategies have helped you find a healthy balance? Share your experiences and tips in the comments below—your story could help someone else on their journey to better health.
And remember: when it comes to your well-being, moderation and support are always in style.
Also read: Want a healthier gut? Try these five dietitian-approved snacks that cost less
