8 black foods: Nutritional powerhouses Fruits, veggies, legumes, seeds and grains tinged with such a deep purple that they appear black are nutritional powerhouses. Delight in these dark foods. By Matthew KadeyPhotography by Ryan Brook/TC Media Slide: 1 of 8 auto-play pause next first speed Black chia seeds These little seeds are an excellent source of heart-healthy omega-3 fatty acids and fibre (roughly 10 grams in a two-tablespoon serving). "Since fibre increases the feeling of fullness, it helps prevent overeating,"says Jennifer Broxterman, a registered dietitian and owner of NutritionRx in London, Ont. Sprinkle the mildly nutty seeds into yogurt, oatmeal and smoothies. Or use ground chia seed powder in pancakes and muffins.