UNSATURATED FATS These are divided into two groups, monounsaturated and polyunsaturated, both of which are good for you.
Examples are: Monounsaturated - olive, peanut, almond and avocado oils, pumpkin and sesame seeds.
Polyunsaturated - fish, walnut and sunflower oils.
Omega 3 oils are in this category.
SATURATED FATS The main ones we consume and need to cut back on are Fatty meats, full cream dairy products especially butter, coconut oil TRANS FATS These are the ones that cause the most harm.
Really cut these back only using as a special treat.
A trans fat is a normal fat molecule that has been twisted and deformed during a process called hydrogenation.
During this process, liquid vegetable oil is heated and combined with hydrogen gas.
Partially hydrogenated vegetable oils are more stable and less likely to spoil, which is very good for food manufacturers-and very bad for you.
No amount of trans fats is healthy.
Trans fats contribute to major health problems, from heart disease to cancer.
The main sources are · Margarine - the solid form · Baked goods - biscuits, crackers, cakes, muffins, pie crusts, pizza dough, and some breads like hamburger buns · Fried foods - doughnuts, French fries, fried chicken, chicken nuggets and battered fast foods · Snack foods - potato chips; sweets; packaged or microwave popcorn · Solid fats - stick margarine and semi-solid vegetable shortening · Premixed products - many contain hydrogenated oils You need to be a trans fat detective and look for the words "hydrogenated oil" on the label ingredients.
Many good oils are changed in this fashion to become dangerous.
So with this sort of information what should we do? A suggested rule of thumb is

• Keep total fat intake to 20-35% of calories
• Limit saturated fats to less than 10% of your calories (200 calories for a 2000 calorie diet)
• Limit trans fats to 1% of calories (2 grams per day for a 2000 calorie diet)

What specific things do I do to try to use good fats?

• Use an olive oil based soft spread - not butter or margarine
• Make up my own dressings based around virgin olive oil
• When cooking use a high smoke point / low saturated fat oil
• The best are avocado or rice bran oils - I use rice bran as it is often on special at supermarket
• Eat less red meat and more fish and chicken
• Go for lean cuts of meat
• Bake, broil, or grill instead of frying.
  
• Remove the skin from chicken and trim as much fat off of meat as possible before cooking.
  
• Avoid breaded meats and vegetables and deep-fried foods.
  
• Choose low-fat milk and lower-fat cheeses like edam

An additional point is about olive oil.
It is a great product and has some valuable components in addition to being an unsaturated fat.
But to get the best from it you need to use the right grade for the right purpose Virgin or extra Virgin - use this for dressings or any cold use, it has the best flavour and the most extra value components.
Don't cook with it as if over heated can produce some trans fats Light or very Light - less flavour and other components but higher smoking point and better to cook with (still prefer rice bran or avocado).
So to summarise.
Food is not only essential but also an important pleasure in our life.
But we need to try to eat in a healthy manner and eat the less desirable foods only on special occasions and as special treats.
It is not the end of the world to have the odd feed of fish and chips or some biscuits or snacks.
Just restrict their intake.