Milled flaxseed may be used as a fat substitute in most recipes. Generally, 3 tbsp. milled flaxseed can replace 1 tbsp. fat or oil.
An easy way to get more flaxseed in your diet is to grind the seeds in a spice or coffee grinder and add the ground meal to muffins, breads, or other baked goods.
Additionally, 1 tbsp. milled flax plus 3 tbsp. of water can replace 1 egg. Adjust as needed for your recipe.