There is much research continuing in the whole area of fats in the diet, but my current suggestions are:
Frying and Roasting: If you want to cook foods at high temperatures the most stable fats are the saturated fats, and recent research is showing virgin coconut oil to be the oil of choice. Look to buy organic, virgin coconut oil as cheaper 'pure' oils may be refined and heat treated, reducing any health benefits. Where there is no dairy allergy, butter may be used in cooking in small amounts, but don't make fried foods a regular part of the diet.
Steam frying: Olive oil may be used where temperatures do not get too high, so to prevent oxidation add a tablespoon of water if you are frying with olive oil. Adding a lid to the pan will prevent the water from evaporating and keep cooking temperatures low. This method is useful when preparing onions, garlic and peppers etc before adding to a recipe, or for stir-frying.
Baking: Experiment with coconut oil in baking recipes, perhaps using some butter as well. Where baking temperatures are low olive oil may be used. If baking/roasting meat or vegetables with olive oil, use low temperatures and adding some water or stock will help keep temperatures low, minimising oxidation.
Drinking: A 2006 study by Ellis et al, showed that organic milk contains more polyunsaturated fatty acids and essential fatty acids (especially omega 3) than conventional milk. Although milk is not on the diet plan for most Nutritionhelp clients, those who eat yoghurt and cottage cheese may like to look out for organic varieties. Likewise, those with families may like to favour organic milk for children.
Spreading: Butter is the natural, untreated fat, low in trans fatty acids, but this isn't suitable for those with a dairy allergy or with a lot of inflammation. For an alternative 'margarine' try mixing 2 parts virgin coconut oil to 2 parts extra virgin olive oil. Keep refrigerated but it will spread straight from the fridge and is a good way of including the health benefits of both olive oil and coconut oil in the diet. If you find this ratio is too oily when making sandwiches etc in advance, try using 3 parts coconut oil to 1 part olive oil. Another type of 'spread' can be made by finely grinding seeds (eg sesame, sunflower, pumpkin, linseed), either individually or in combination, and then mixing with a very little water to obtain a spreading consistency.
Salad and vegetable dressings:Extra virgin olive oil has a reputation for benefiting heart health, and this is a great oil to use on jacket potatoes and in salad dressings. You may also like to experiment with other unrefined, cold pressed oils, but Flax seed oil is the only seed oil that includes substantial levels of omega 3, most other seed oils being higher in omega 6 fatty acids. A salad dressing useful for most Nutritionhelp clients is to mix two parts extra virgin olive oil with 1 part lemon juice. Add mixed herbs, black pepper, onion granules/powder, or a crushed clove of garlic to taste. This dressing can be used freely over cooked vegetables or salad. You may like to experiment with replacing some of the olive oil for flax seed oil or hemp seed oil (often sold as 'Good oil' in super markets)
Foods: Snack on raw seeds as a great source of nutrients and omega 6 oils. Avoid roasted seeds as heating may cause the delicate polyunsaturated fats in the seeds to oxidise. Include oily fish regularly in the diet, omega 3 guidelines being met with 2 -4 portions a week. In order to minimise ingesting pollution avoid tuna and sword fish and favour the smaller oily fish, such as wild salmon, trout, sardines and pilchards.