The Worst Foods For Your Brain

Likely sources: Dairy, desserts and the chip-and-dip combos you dig into at parties.

What they have in common: They're high in fat.

Science says: The list of healthy fat's benefits continues to grow. But a diet that's too high in total fat may affect your emotions, according to research in the International Journal of Obesity. Mice put on a high-fat diet (58 percent of their calories came from fat) developed signs of despair, anxious behavior and increased levels of a protein that's known to be higher in depressed people (brain-derived neurotropic factor). And saturated fat may be particularly harmful, says study co-author Stephanie Fulton, PhD, associate professor of nutrition at the Montreal Diabetes Research Center at the University of Montreal.

The amount that's okay to eat: Aim to get between 56 and 78 grams of good-for-you mono and polyunsaturated fat per day (think fish, nuts and avocados). Cut off daily saturated fat at 16 grams (the amount you'd get from three slices of cheddar cheese). (Based on a 2,000-calorie-per-day diet).