The Interactive Effects of Fat Calorie Proportion Under Different Dietary Calorie Levels on Depression

In recent years, the total number of people with depression worldwide has been on the rise. Among the factors influencing depression, the relationship between diet-related factors and depression has become one of the hot topics. To our knowledge, in this field, no prior study has investigated the combined effect between fat calorie proportion and dietary calorie levels for relevant research, so the conclusions are still unclear. The data for this study came from the 2017–2018 National Health and Nutrition Examination Survey (NHANES), including Energy (kcal), Fat (gm) and Depression. Drawing on the data obtained above, in our study, we first categorized the sample into three groups based on energy intake levels. Then we converted the fat intake data into the energy contributed by fat and combined it with the total energy intake data to calculate the proportion of energy derived from fat relative to total energy intake. These three main variables—dietary calorie levels, fat calorie proportion, and their interaction—were subsequently analyzed in relation to depression. The final study sample included 2,786 adults. Binary logistic regression was used to study the interactive effects of fat calorie proportion under different dietary calorie levels on depression. After multivariate adjustment, the proportion of fat calories and their interaction with different dietary calorie levels were not significantly associated with depression. However, we found that when only considering different dietary calorie levels and the adjusted variables, high dietary calorie intake (OR: 0.571) was associated with reduced odds of depression. This study provides a reference for developing dietary plans in mental health interventions and explores the link between caloric intake and depression from a fresh angle. Also, it introduces a novel research paradigm in the field of nutritional psychiatry.