In order to lose body fat and maintain a healthy lifestyle, you must observe the ratio of the types of fat you consume and what kind you consume. Polyunsaturated fats are necessary but, you must consume them with food and in certain ratios. Omega-3s are a unique type of polyunsaturated fats that help you lose fat and also prevent you from gaining fat. These aren't typical polyunsaturated fats so disregard what I said earlier when eating these types. The intake should be adjusted depending also on age; the older one becomes, the more fish oil and the less alpha-linolenic and alpha linoleic acid they need. The reason for this is that some enzyme activities that help in the conversion of these fats into "active" fats decreases with age.


Always remember to consume alpha linoleic and linolenic acids because they are essential to life; the body can make other fats from these fatty acids, but it can't derive them from other sources (they must be provided by your diet). Consuming more olive oil or other monounsaturated fats than saturated or polyunsaturated fats is also beneficial.
Make the consumption of 0mega-3 essential fatty acids your main priority. Stay away from high-saturated foods and keep your flax oil intake at a low leveif your main goal is to lose weight. Reducing the intake of polyunsaturated and saturated fats and consuming high foods high in alpha linolenic (ALA) flax, walnuts, fatty,  fish along with moderate consumption of olive oil ought to provide you with the tools you need to achieve and maintain a healthy lifestyle.
Some general guidelines:
1. One tablespoon of flax oil per day.
2. Two to three tablespoon of olive oil per day.
3. One fish oil softgel per 20 Ibs of bodyweight per day.
4. Keep all the other dietary fat consumption low.