Is Dieting Hurting Your Mental Health? Here’s What the Latest Research Shows Experts explain why, and share how to protect your mental health while dieting
A new study found a link between calorie-restricted diets and more depression symptoms
Daniel de la Hoz / Getty Images
- In a new study, people on a calorie-restricted diet reported more depression symptoms than those on other diets or not dieting.
- Nutrient gaps and a lack of emotional support may explain why dieting makes some feel depressed.
- Experts recommend balanced, sustainable diets to support both mental and physical health.
Dieting is usually associated with better physical health, but a new study suggests that eating plans that focus on restricting calories may actually worsen mental health.
The research, published June 2 in the journal BMJ Nutrition, Prevention and Health, found that nearly 30,000 people on a calorie-restricted diet were more likely to report depressive symptoms than those on other diets or not dieting at all.
Depression can result from many factors, and diet’s influence on the mental health condition is a relatively new area of scientific research. This study adds to our understanding of how food choices made in everyday life might affect depressive symptoms, Venkat Bhat, MD, MSc, study co-author, staff psychiatrist, and director of the Interventional Psychiatry Program at St. Michael’s Hospital in Toronto, told Health.
A New Way of Studying Diet and Depression
Previous studies have shown a link between reduced depressive symptoms and following carefully designed eating plans like the Mediterranean diet, which focuses on nutritious and minimally processed foods.
But, according to the new study’s authors, little research has investigated how the more varied diets people try in the “real world," outside of a controlled research setting, might affect mental health.
“Many individuals adopt restrictive dietary patterns like low-calorie, nutrient-restricted, or condition-specific diets for perceived health benefits, yet the mental health impacts of these common but less idealized dietary strategies are understudied,” Bhat said.
To fill this gap, researchers turned to the National Health and Nutrition Examination Survey (NHANES), a questionnaire designed to assess health and nutritional status in the U.S. The team analyzed the dietary habits of 14,329 women and 14,196 men from 2007 to 2018 and their responses to the Patient Health Questionnaire-9 (PHQ-9), a survey used to gauge the severity of depressive symptoms.
Based on the responses, researchers divided dietary patterns into four categories:
- Calorie-restricted diets
- Nutrient-restricted diets, such as those low in fat, sugar, carbohydrates, or sodium
- Established diets such as diabetic or DASH
- Not on a diet
What Researchers Discovered
After crunching the numbers, the scientists found that most people didn’t follow any particular diet. Meanwhile, 8% adhered to a calorie-restricted diet, 3% were on a nutrient-restricted diet, and about 2% followed an established dietary pattern. About 8% of respondents reported depressive symptoms.
There was no significant association between nutrient-restricted or condition-specific diets for diabetes and depressive symptoms. However, those on calorie-restricted diets, especially men and people who were overweight (but not obese), tended to have higher PHQ-9 scores compared with those not on any diet.
Digging further, researchers found that overweight individuals on nutrient-restricted diets had higher PHQ-9 scores, indicating more severe depressive symptoms.
Men following nutrient-restricted diets also had higher somatic symptom scores—reflecting distress and anxiety about physical symptoms—and higher cognitive-affective scores, which measure the relationship between thoughts and emotions, compared to women not following a diet.
“This is a particularly interesting finding because it suggests that while calorie-restrictive diets may improve depressive symptoms in research trials, they could worsen depressive symptoms in real-life settings,” Marta Mudd, MD, PhD, chief resident, PGY-4, psychiatry at McGaw Medical Center of Northwestern University, told Health.
The Limitations
It’s important to remember, however, that the study is observational—meaning it can establish an association between restrictive diets and worsening depressive symptoms but doesn't prove causation.
The study was also limited in that self-reported dietary habits can be inaccurate. The researchers also didn’t assess how weight loss—independent of the chosen diet—may have affected depressive symptoms, Maryam S. Makowski, PhD, FACN, a clinical associate professor in the Department of Psychiatry and Behavioral Sciences at Stanford University, told Health.
Why Might People Feel Worse While Restricting Calories?
Mudd said people might feeling depressed while dieting if they cut calories at the expense of essential nutrients. Not getting enough calories—or a sufficient variety of vitamins and minerals—can lead to nutrient deficiencies and physiological distress, which in turn may worsen depressive symptoms, she explained.
“Our cognitive performance and mood can begin to suffer from the effects of a poor diet long before we notice physical symptoms elsewhere in our bodies,” Makowski added.
According to Bhat, nutritional deficiencies may help explain why the study found that men were more likely to experience worsening depression on restrictive diets. Men have higher nutritional requirements than women, and deficiencies in key nutrients crucial for brain and mood regulation—like omega-3 fatty acids and B vitamins—might exacerbate depressive symptoms, he added.
Studies have also suggested that low-calorie diets alone don’t improve depressive symptoms unless they lead to significant weight loss and include behavioral therapy—something that Mudd noted doesn’t always happen in the real world.
“Prior findings may not translate to reality, where individuals who are dieting can experience insufficient support and motivation, lack of weight loss, and weight cycling, all of which can worsen depressive symptoms,” Mudd said.
Protecting Your Mental Health While Dieting
The study’s main takeaway is not to avoid dieting but to pay attention to nutrition and avoid unsupervised, overly restrictive dieting, Mudd said.
Dieters need to remember that weight loss is not just a physical journey but an emotional and psychological one, too, Makowski added.
To minimize mental health risks from dieting, Mudd advises:
- Using balanced and sustainable calorie reduction
- Prioritizing whole foods that meet nutrient needs
- Closely monitoring for signs of worsening mental health
Additionally, Mudd and Makowski suggested working with healthcare professionals who can develop personalized nutrition plans and offer mental health support.
“By collaborating with professionals who specialize in these areas, patients can receive tailored guidance that addresses their unique needs and challenges,” Makowski said.
Jani Hall
Jani Hall is a news editor for Health with a background in health, science, and investigative reporting. Previously, she wrote full time about parenting issues for the app Parent Lab. Before that, she worked as a reporter for National Geographic covering wildlife crime and exploitation.
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This story originally appeared on: Health News - Author:Cathy Nelson
