A recent study has found that an increase in depressive symptoms is associated with a subsequent increase in body weight when measured after one month. The study, conducted by researchers from the University of Cambridge, was published in the scientific journal “PLOS ONE” and reported on by the website “Science Daily.”
The researchers stated that this increase was only observed among individuals who already suffer from overweight or obesity. However, they did not find any connection between having more pronounced depressive symptoms and an increase in body weight in general.
Previous research suggested a link between weight and mental health, implying that each could affect the other. However, this relationship is complex and not well understood, especially concerning how changes in an individual’s mental health might impact body weight over time.
To help answer this question, researchers at the Medical Research Council’s Epidemiology Unit at the University of Cambridge examined data from over 2,000 adults living in Cambridgeshire, UK.
The participants completed digital questionnaires regarding mental health and body weight each month for up to nine months during the COVID-19 pandemic (August 2020 – April 2021) using a specialized mobile app.
Assessing Depression Symptoms
The questionnaire assessed symptoms of depression, anxiety, and stress in individuals. Higher scores indicated greater severity, with the maximum possible scores being 24 for depression, 21 for anxiety, and 40 for stress.
Researchers found that for every one-unit increase in an individual’s usual score for depression symptoms, their subsequent weight increase after one month amounted to 45 grams. While this may seem minimal, it means, for example, that someone whose depression score increased from 5 to 10 (equating to a transition from “mild” to “moderate” symptoms) was associated with an average weight gain of 225 grams.
This effect was observed solely in individuals who are overweight (defined by a Body Mass Index of 25-29.9 kg/m2) or those suffering from obesity (BMI greater than 30 kg/m2). On average, individuals who were overweight had an increase of 52 grams per point increase in their usual depression symptom score, and those with obesity had a comparable weight increase of 71 grams. The effect was not seen in individuals with a healthy weight.
The lead author, Dr. Julia Muller from the MRC Epidemiology Unit, stated: “Overall, this suggests that individuals who are overweight or obese are more prone to weight gain in response to feelings of depression. While the weight gain was relatively small, even minor changes in weight accumulated over more than a year can lead to more significant weight changes in the long term, especially among those who are overweight and obese.”
Short-term periods could lead to more substantial weight changes over the long term, particularly among those already overweight or obese. “People with a higher BMI are already at greater risk for other health conditions, so this could lead to further deterioration in their health. Monitoring and addressing depressive symptoms in individuals who are overweight or obese could help prevent further weight gain and be beneficial for their mental and physical health,” added Muller.
Researchers did not find any evidence that stress or anxiety correlates with changes in weight. While previous studies implied that mental health issues could cause and result from obesity, the research team did not find evidence that weight predicts subsequent depressive symptoms.
