It’s official: Your diet is making you depressed, according to science

Skipping dessert really can leave you down in the dumps.

No one who’s been on a diet has ever said, “I love calorie restriction,” but a new study has found a not-so-surprising link between low-cal eating and depression.

And some people have it worse than others.

The dietary habits and depressive symptoms of 28,000 US adults were analyzed for the study, published in BMJ Nutrition Prevention & Health.

Of these adults, 29% had a healthy weight, 33% were deemed overweight, and 38% were considered obese.

The dietary patterns were divided into four categories: calorie-restrictive, nutrient-restrictive (AKA low in fat), sugar, salt, or carbs, established dietary pattern, or not on a diet at all.

The majority of participants, 87%, did not follow any specific diet, 8% followed a calorie-restrictive diet, 3% opted for nutrient restriction, and 2% followed an established dietary pattern.

Using questionnaires from the US National Health and Nutrition Examination Survey, researchers found that 8% of participants reported depressive symptoms.

Those on calorie or nutrient-restrictive diets exhibited higher scores of emotional and physical distress than their cohorts who were not on a specific diet, suggesting that unsupervised restrictive diets may negatively affect mental health.

Researchers found that men and those whose BMI classified them as overweight were particularly susceptible to diet-linked depression.

“The findings suggest caution with overly restrictive or unbalanced diets, particularly for people already experiencing weight-related stress or challenges,” said lead study author Dr. Venkat Bhat, psychiatrist, clinician-researcher, and director of the Interventional Psychiatry Program at St. Michael’s Hospital and University of Toronto.

Researchers found that the quality of diet had a direct bearing on depression risk. Those whose diet was rife with ultra-processed foods (UPFs) were more likely to report higher levels of depression.

Recent research revealed that 60% of Americans’ daily caloric intake comes from ultra-processed foods.

UPFs often contain high levels of sodium, refined sugars, cholesterol-spiking fats and other lab-based ingredients.

A 2023 study from the Harvard T.H. Chan School of Public Health found that people who consume nine or more servings of UPFs a day have a 50% higher risk of developing depression than those who eat four or fewer daily servings.

In contrast, this latest study revealed that those who followed a Mediterranean diet exhibited lower rates of depression.

Previous studies have established that a Mediterranean diet rich in fruit, veggies, nuts, fish, and plants can slash depression risk by a third.

In a 2023 Gallup poll, 29% of US adults reported having been diagnosed with depression at some point in their lifetime, while 17.8% of Americans said they have depression or are being treated for it.

Besides affecting your quality of life and relationships, depression can raise the risk of heart disease, diabetes, stroke, dementia, Alzheimer’s disease, anxiety disorders and substance abuse.

Given the results of this study, Bhat suggests dieters abstain from strict caloric restriction and instead opt for,“ balanced, sustainable dietary changes that meet nutritional needs.”

Researchers note that their findings only reveal associations, not definitive data. Further, due to the survey format, there’s no way to verify that participants truly adhere to caloric restriction.

Still, Bhat and his team are hopeful that future studies will continue to examine the relationship between calorie restriction and mental health.