According to a recent study published in The International Journal of Obesity high-fat diets may lead to “depressive-like behaviour”. This study, which looked at a comparison of mice fed a low-fat diet and mice fed a high-fat diet, found that mice on the high-fat diet exhibited certain depressive-like behaviours. These included avoiding open areas and increased immobility during a swimming test. Of course, these results were reported as Rich, fatty comfort foods can lead to depression, study finds in the Globe and Mail. Now, it may well be true that a high-fat diet can increase risk of depression but it’s a huge leap to make that conclusion based on this study. Firstly, the study was looking at mice not humans. Any sort of animal study may not be directly translatable to humans, and laboratory conditions certainly do not mimic conditions of our daily lives. Secondly, the study found the high-fat diet led to depressive-like behaviour not depression. There is a huge difference there. A little bit of lethargy may be a sign of depression but is not necessarily clinical depression. Thirdly, it’s difficult to compare the diet the mice were fed to our diet and even more of a stretch to say that “comfort foods” can lead to depression. I doubt that these mice were being fed mac and cheese or doughnuts to up their fat intake (and even if they were, who are we to say what constitutes comfort food for a mouse?). Finally, the researchers made the mice obese, it wasn’t just the consumption of fatty foods that caused them to exhibit “depressive-like behaviour”. We can’t say if it was the high-fat diet that made them exhibit these behaviours or simply the obesity which could be caused by the over consumption of any or all macronutrients. So, do rich, fatty comfort foods make us depressed? I don’t know. I sure can’t tell based on this study alone. My advice, eat a balanced diet including carbs, protein, and fat and don’t worry too much that you’re going to develop depression because you indulged in a cookie.